Cold Weather Advisory:
A Detailed Look at the Question of Supplemental Heat
As autumn rolls around, and many of us start thinking about the winter ahead, one question seems to come up more than others: Do my chickens need supplemental heat for the wintertime? To answer this question with a simple yes or no would be depriving many people of the information they need to make an informed choice about it for their own, and indeed may lead to many going into heating their coops without taking into consideration the risks of doing so.
My goal in writing this page is to show why chickens generally do not need heat for the winter, list what exceptions there are to that rule, and explain the many risks and considerations that you need to keep in mind if you decide to go ahead with adding supplemental heat to your flock anyway. I am not a veterinarian, and I also cannot say for certain what the needs are of any other species, but I have an abundance of experience surviving the winter with chickens—and I have put in countless hours of research to make sure my birds are safe!
To begin with, I would like to look at the birds, themselves, and explain how they stand the coldest winters.
Adaptations to the Cold
It’s a common misconception that because we feel cold in wintertime, our chickens do as well. The fact is, birds like chickens are very different than mammals like us, and chickens have excellent adaptations to handle the cold!
What can be noticed the most is behavioral adaptations. You may see your chickens huddling together for short periods of time, keeping their feathers fluffed out, even tucking their faces in under their feathers when the temperature is particularly low. These are not causes to be alarmed, but natural behaviors to help the birds keep warm!
Other behaviors, perhaps less noticeable, are as simple as facing into the wind, angling their bodies to the sun, and drawing one foot up into the feathers or sitting down and covering both feet with feathers. By facing the wind, the birds prevent their feathers from lifting up. Feathers will be discussed more thoroughly in the next section, but by having the wind lift their feathers, a bird can lose heat. As well, by standing at just the right angle to the sun, a bird can maximize the amount of surface area is receiving heat from the sun. And finally, by covering one or both feet (and tucking away their face as was mentioned in the above paragraph), the bird is significantly reducing the amount of bare, featherless skin that is exposed to the cold.
What behaviors are not considered normal? If a bird is stumbling when it walks or unable to maintain its balance, it needs immediate help! Other signs that might be significant are if a bird is sleeping a lot more than the others or generally not acting right, or if a group is huddling for long, long periods of time (think hours--not minutes!). Any of the behaviors mentioned above, if continued for very long periods of time, could also be cause for concern. What is best for the flock, unless you have a very small flock anyway, is to have another pen ready to heat and move only individuals that struggle to that pen, lowering the overall risk to the flock.
Roha, an Exchequer Leghorn, in both cold and warm weather. On the left, she is in cold winter
weather; she has fluffed out her feathers and drawn her neck in close to her body. On the right, she is in
relatively warmer fall weather; her feathers are smoothed out and flattened to her body.
In the cold, many animals can restrict the blood flow to their extremities to prevent losing heat in their core. By doing so, however, they risk severe frostbite in those extremities and it can result in some uncomfortable conditions. For birds, however, this works a little differently. Though they, too, can restrict blood flow in order to prevent heat loss, they take this a step further.
The veins and arteries in a bird’s feet are wrapped closely together, allowing for what is called countercurrent heat exchange. As the cold blood moves through the bird’s veins back toward its core, and the warm blood leaves the bird’s core toward its feet, the blood passes closely in the veins and arteries and in doing so it exchanges heat. Basically, the warm blood warms up the cold blood before it goes back into the bird’s core and the cold blood cools down the warm blood as it moves toward the feet. In this process, the bird lowers the amount of energy spent warming its blood back up as well as lowering the amount of heat lost to the air through the exposed skin of the feet.
Perhaps the most well known of birds’ adaptations are those unique and ingenious feathers! Feathers come in many shapes and sizes, perfectly adapted for many habitats across the planet, and even a single species of bird has many different kinds of feathers on it! For the purposes of this page, I will focus mainly on the types of feathers that matter most in wintertime: contour, semiplume, and down feathers.
Various feathers from my flock.
Most feathers consist of at least two of three parts; all feathers have a shaft, and most have either a vane, down, or both. The central shaft is what gives the feather its shape and attaches it to the bird. The vane is the flat, smooth section of the feather toward the top, and the down is the fluffy, loose part at the bottom of the feather. Down feathers, as you probably are aware, consist entirely of down with a soft and flexible shaft. Contour feathers have a vane and some down on a stiffer shaft. Semiplumes are somewhere in the middle, with more down and less of a vane that is not held together as smoothly compared to contour feathers.
Left to right: a down feather, a semiplume feather, and a contour feather.
The parts of the contour feather are labelled (the quill is the tip of the shaft).
How these feathers help keep a bird warm is simple. The vane of the contour feathers forms a tight, sealed barrier from the outside air, restricting the heat the bird produces from leaving its body. The downy section of all of these feathers then traps that heat beneath that barrier, and holds it close to the bird’s body. By fluffing out their feathers, chickens produce an even thicker layer of insulation—and as long as the vane barrier is uninterrupted, that heat can be held onto easily to maintain the bird’s body temperature.
Feathers are such excellent insulators that you may notice that the surface of your birds’ feathers actually feels cool to the touch in cold weather. Want to know how cold your chickens really are, though? Lift up your bird’s feathers and put your fingers down into their down near their skin. It’s quite warm in there, isn’t it? This is also the reason why chickens struggle more in extreme heat than in cold. It’s easy to keep in the warmth they produce, but releasing it is more difficult!
Risks of Adding Supplemental Heat
There are numerous risks to adding heat, but I will keep this section down to only some of the most cited risks around the forum.
Possibly the most cited reason against adding supplemental heat to the coop is the enormous fire hazard in doing so. This risk can be lowered by knowing the dangers and what to look out for, but in many cases there are dangers no matter how you prepare to heat the coop, mainly depending on what you use to supply that heat.
Heat lamps, particularly those containing 250 watt bulbs, are the cause of many, many coop fires each winter, and this is simply because as a whole they are not safe. Metal clamp lamps fall apart easily and can fall into bedding, igniting it. Many times, dust landing on the bulb or the fixtures in the lamp can ignite as well. There are many reports of bulbs exploding or shattering as well, causing the added risk of broken glass in the bedding of your coop. A safer alternative would be to invest in a heat plate or other self-contained heating device. Be aware of the possibility of fumes and don't close anything that may put them out in your coop with your birds!
Another big fire risk, as mentioned above, is simply the act of running electricity to the coop, especially through extension cords! If at any point an animal (such as a mouse) decides to chew on a cord, it opens up wires and allows for the cord to short out or ignite anything that gets too close. Any dust that gets into the outlets poses a fire risk as well. Fire safety with electricity is discussed in a later section of the article.
Remember, chickens are active, dusty, clumsy creatures! If there is a way for them to knock around their heat source, more than likely, they will find it!
Acclimation to the Cold
When providing heat to your birds, you are robbing them of the opportunity to acclimate to the cold. This may not seem like a big deal, but in many areas, the power is often knocked out over the winter and it leaves these birds unprepared for the sudden change in temperature.
This comes with an additional concern, in that your birds will most likely not want to leave their coop for any length of time if they are used to the supplemental heat. This raises the risk of boredom amongst your birds potentially leading to feather picking or cannibalism, buildup of excess moisture from extra droppings and the birds breathing, and lowered activity and exercise.
Many, many people have also found that by providing heat, you are preventing your birds from preparing themselves for the cold in another way. It is believed that chickens will grow more down when exposed to cold weather, thereby preparing themselves for what is to come. If they are in a heated coop, they will not have that pressure to grow extra down, and so will be even less likely to leave the coop and even less prepared for power outages and temperature changes. This is more of a personal experience by some farmers, however, and so whether you feel it to be credible is up to you.
As was mentioned in the above section, if your birds are huddled inside all day, it can allow for excess moisture to build up in the coop. On top of this, the warmth from supplemental heat allows more of this moisture to stay in the air than will in cold air. This excess moisture is not only unhealthy for chickens on its own--even in the summertime!--but can lead to issues with frostbite if that moisture condenses on exposed combs and wattles. Moisture and cold in combination wreak havoc on vulnerable combs and wattles during the wintertime! In the worst conditions, your birds may also get frostbite on their toes!
Rangi, my young Ancona, recovering from frostbite. Her frostbite is an extreme
case resulting from moisture building up in the coop after a flood, but similar
issues can arise from inadequate ventilation, especially when combined with
heat allowing that moisture to stay in the air.
The best way to lower that risk is to make sure there is plenty of ventilation to allow that moisture to escape--the more draft-free ventilation, the better! In doing so, though, you will likely lose heat from the coop as well—and the money you are paying into providing that heat! These are things that one must be take account of when deciding whether or not supplemental heat is right for their flock (and their budget).
It should be noted that the above about frostbite is in regards to winters in which it gets as low as a little bit into the negatives, Fahrenheit, at the lowest. Please see the below section about temperature extremes.
As with everything, there are exceptions to strictly avoiding heat in the coop. It would be a big mistake to not bring this aspect up and clarify that not every flock has the same requirements!
Certain breeds are known for being less cold-hardy for one reason or another. Mostly, people seem to agree that breeds with large single combs are most vulnerable to the cold, although this has not been my personal experience. In fact, the breeds that seem most at risk in cold weather are the lighter, smaller bantam breeds, such as game bantams and Seramas.
Bantams tend to be less hardy in cold conditions simply because they are producing less heat for themselves than a large fowl bird is. Now, many, like bantam Faverolles, Ameraucanas, Brahmas, Cochins, Orpingtons, Wyandottes, and several more, are perfectly adapted to the cold with thick feathering for insulation, and as such they shouldn’t need help. Some bantams, however, are thinner and less fluffy, and as such they have less insulation from the cold. Many will adapt just fine and will not need supplemental heat, but it is advised that you keep a close eye on bantams in the coldest temperatures and be ready to act if they need help.
Though in a lot of cases, I must disagree with the consensus that any particular breed is not cold-tolerant, there are certain breeds that beyond a doubt are at a higher risk in cold weather. Mainly, this is because of their feather structure.
As you are likely aware, there are certain breeds of chickens that have unusual feathers. While in most breeds, the feathers are absolutely perfect to hold in heat and insulate against the cold, certain breeds have feathers designed a bit differently. The most commonly cited feather types that are believed to have difficulty in the cold are frizzles, silkies, and hardfeathers. Frizzles, with their curled feathers, are less able to hold in heat as a result of lacking that solid feather barrier as was explained above. Though I have read many cases where frizzles have done fine in cold weather, it's worth pointing out that a close eye should be kept on them just in case. As well, hardfeather breeds like certain game breeds may have difficulty in the cold because they have harder, less downy feathers built more like armor, and those feathers can’t insulate as well as soft feathers.
And Silkies? Well, Silkies and other silkie-feathered breeds are lacking the barbules that hold the vane of the feather together, producing an overall downy appearance. Whether this makes them less able to handle the cold or not is debated. Many people insist that silkied feathers don’t hold heat, while others say they hold heat better than regular feathers. Logically, by looking at the structure of the feather, it can be assumed that Silkies would have a harder time holding in heat because they lack the solid part of the feather that forms a barrier between them and the cold. Personally, though, as the owner of one Silkie who took the cold in her stride and didn’t bat an eye when we dropped beneath 0 degrees F, my experience has been that they can handle the cold just fine. In the case of Silkies, as with other bantams, it is probably best to provide them a draft-free shelter and watch them closely for issues rather than supplementing heat preemptively. After all, one of the most cold-hearty varieties of chickens can have silkied feathers!
Margaret, my Silkie, during the bitter cold winter we experienced in early 2014, here in Indiana.
This is fairly common sense, but I thought I would add it nonetheless. The age of the bird will effect its ability to survive in the cold. Obviously, you don't want to put chicks outside in the wintertime without some source of supplemental heat! In my experience, once a pullet or cockerel is fully feathered and has been allowed to gradually acclimate to temperatures with the seasons changing, he or she should do fine in winter temperatures.
Another thing to keep in mind is that very old birds may not be able to handle the cold anymore, either. Most birds in my flock that have reached advanced ages have handled cold just fine into their final years, but as always, there will be exceptions! One aged hen that I owned spent 9 1/2 years of her life not letting anything get her down, and then one winter she just couldn't take the cold anymore. Any time it dropped beneath freezing, she was blue-faced and stumbling around. She was the only aged hen I ever owned to have problems with the cold in her old age.
As always, make sure to keep an eye on very young and very old birds to be sure they're handling the temperatures fine!
Many people are inclined to heat their coop as soon as it hits 32 degrees F or lower. However, even when the temperature drops below freezing, generally you don’t have anything to worry about just yet except for frozen waterers. Even down to 0 degrees F and below, most breeds will be just fine. The best strategy in these conditions is to employ observation, and provide a separate pen with heat only for the birds that appear to be struggling, lowering the risk to the entire flock.
As the temperature drops further and further into the negatives, however, it becomes more and more likely that your flock will need help, and you may see some frostbite just out of the sheer frigid cold rather than as a result of a buildup of moisture in these conditions. The most cited temperature minimum that people use as a point at which you could intervene is -20 degrees F (that is, 20 below 0), though even that is up for debate, with some saying that their birds are fine at even lower temperatures. However, it is understandable to want to add heat in these conditions, and especially when it gets even lower! This is one big reason why the below section is also included on this page.
Safety when Providing Supplemental Heat
Even with all of the above in mind, and especially in conditions where the temperature reaches extreme lows, you may decide to provide heat anyway. That is entirely your choice for your flock, and not one to be ashamed of if you are at least keeping in mind the many risks and dangers, and doing what you can to prevent them!
As was mentioned above, chickens are very clumsy, very dusty, and very skilled at increasing what risks may be within their reach. When you are providing heat for your birds, you have to keep this in mind.
First and foremost, do your best to lower the fire risk of providing heat. Make sure you have securely attached your heating devices to the wall or ceiling of your coop so that they cannot fall into the bedding and risk setting the coop on fire, and cage any heat sources that may get hot to the touch o prevent vulnerable feet and combs from coming into contact with it. If you are using an extension cord, make sure it is rated for outdoor use and can handle the amount of electricity going through it. Whether you use an extension cord or not, frequently check the length of all cords for wear and tear and dust all outlets often. It is also important no matter what you use to heat your coop that you dust it regularly and inspect it often for any signs of failure.
Due to the overwhelming evidence, it must be said that using the metal clamp lamps from the feed store with a 250 watt red bulb is seriously asking for a fire. Specifically, the 250 watt bulb gets way, way too hot if left on for long periods and can pose a fire risk even if it does not fall, simply because it can ignite dust that lands on it. There have even been reports of birds flying into these super-heated bulbs and their feathers igniting as a result! I would wholeheartedly recommend that if you insist on heating your coop, you invest in something other than a metal clamp lamp and 250 watt bulb. There is NO WAY to make this setup safe!
Other heaters that I would recommend before even considering a metal heat lamp are flat panel heaters (such as Sweeter Heaters or Brinsea EcoGlows, both of which will save you a lot on your electricity bill!) or oil-filled heaters (with automatic shutoff in case they fall over!). If you think your birds will use them, there are also heated floor mats that can be used in chicken coops. These are more expensive in upfront cost, but a lot safer in the long run, and if you are going to have chickens for years to come and give them heat every winter, why not invest in something safer?
If you are using a lamp, I would recommend a safer, sturdier heat lamp, such as the one found here, preferably with a bulb smaller than a 250 watt bulb. If there are no alternatives for you other than a metal clamp lamp, the only kind to use is one with a ceramic socket, and NEVER one with a plastic socket that may melt. Never ever EVER use light bulbs that are Teflon-coated (also labeled as 'shatter-proof' so read labels closely!) because these bulbs are toxic to birds when heated up. Aim for a ceramic heat bulb or a light bulb of a lower wattage than the 250 watt bulbs, because as mentioned above these huge bulbs are just generally unsafe. Any lamp that is used in a coop should be covered with fencing such as chicken wire, hung as far away from the birds, walls, ceiling, and floor as possible, and secured in multiple ways to prevent it from falling. The goal is to have as many things as possible that have to fail before the lamp will fall and possibly cause a coop fire. This means that relying just on the clamp or hook attached is ill-advised--use chain, metal wire, zip-ties, twine or rope, just anything but the clamp on its own! One of the best pieces of advice that I've seen in regards to hanging a heat lamp in a coop or barn is to hang it as if it will be a permanent structure, not a temporary one. The more work it takes for you to get it down at the end of the season, the more work it will take for your birds to accidentally knock it down and cause a fire while it's in use!
One last thing in regards to heating devices is fumes. As was mentioned in an above paragraph, as well as much higher on this page, you should never use anything that puts off fumes in a closed coop (even with ventilation!) with your birds! Birds are quite sensitive to fumes and this can lead to flock-wide issues or deaths quite quickly! Do your research and make sure your heater is safe before putting it to use in your coop!
The next thing that you need to be vigilant about is power outages. If you provide heat, your birds may become reliant on it, and if the power is cut off, they can suffer as a result. If you lose power (and have no way of restoring it, such as with a backup generator), it is advised that you provide your birds an area that will take the edge off the cold at the very least, whether in a garage, a basement, or perhaps even in a spare room of your house. Be prepared for what you need to do and make sure you are ready for this sort of thing!
Be aware of the humidity level as well if you decide to heat your coop. Moisture in the coop at any time of the year is a recipe for unhealthy birds, and this can be especially so in cold weather as the concern for frostbite is added to the mix. Be sure to maintain plenty of ventilation and keep the bedding in the coop clean and dry. It is advised that water is put outside the coop to avoid any spilling in the bedding or adding moisture to the air.
Another concern is the boredom factor. Be on the lookout for any signs of your birds picking on one another out of boredom, and have some boredom busters ready to put in the coop and occupy your chickens. Boredom, as was mentioned above, can lead to feather picking and cannibalism in your flock, and that is never easy to deal with, especially not in the wintertime!
Marama, an Egyptian Fayoumi, out and about in the snow. Chickens who live in a heated
coop are less likely to come outside in cold weather like this and it could lead to
frustrating behavioral problems related to boredom!
Alternatives to Heating?
There are alternative ways to help your birds survive the winter without the risks of providing supplemental heat. However, some are equally as debated as the great heating versus not heating debate!
Insulation is a big one. Many believe insulation is not a good idea, partly because people may feel the need to insulate the coop entirely and lower the amount of ventilation in the coop. Insulation can help contain the heat that they produce themselves without the fire risk of supplemental heat, but is only safely applied when ventilation is maintained, a fact that many forget when they decide to insulate their coop! Chickens need ventilation at all times, even in bitter cold! As an added note here, make sure all insulation is covered so that your birds don't decide to make a wintertime snack out of it!
An alternative to fully insulating the coop is making an insulated huddle box over the perches. With a huddle box, you are maintaining plenty of ventilation while giving the birds somewhere to huddle in the cold and build up heat. By simply putting three or four walls and a lower ceiling around the perches, you can help capture some of the heat the birds put off at night to keep it near them while they sleep. The same idea can be applied in a huddle box on the ground for during the day, or for non-perchers, though there is no guarantee that your birds will stay in it long enough to reap the benefits of it. Both should be used while remembering to make sure that moisture is not being trapped within them!
For daytime comfort, if the birds are allowed outside, make sure there are plenty of places for the birds to get out of the wind and snow. Prop something solid like a piece of plywood over a doghouse or against a tree for shelter. In enclosed yards, you can even tack plastic sheeting or old shower curtains on the walls (and top if it's not solidly roofed) to block wind and snow from blowing in. Be sure to leave plenty of room open at the top or leave at least one wall open for ventilation!
It is also believed that by feeding certain things to your birds at nightfall, it will keep them warm through much of the night. This is another debated topic, and just as many people say it doesn’t work as say it does. My thought is, as long as you aren’t feeding unhealthy treats in excess and what you are feeding them is not harmful to them, why not? The most commonly cited ‘warming food’ is whole or cracked corn (scratch grains are often mentioned as well). It should be noted here that feeding corn or scratch grains as a sole ration is not a healthy diet, and it should only be given in a few handfuls before roost time if you are trying to take advantage of the warming effect! Another note here, I would advise against the use of Styrofoam for this effect, and for boredom busting as well! Styrofoam is not good for your birds to eat at all! Even disregarding the composition of it, Styrofoam will fill your birds up and pass through them, largely, if not completely, undigested. This will mean that what calories your birds could have gotten from actual food will have been replaced with nothing, and in the winter time your birds need all the energy they can get to survive!
Because it has gained some interest, I thought I would add here a note about sweaters, such as the one seen in the below picture. Due to the fact that they restrict feather movement and don't allow a bird to insulate itself properly, it is advised that you never use sweaters on fully feathered birds in the wintertime. Personally, I wouldn't use a sweater in any case during the winter, as my experience as shown that they do next to nothing for birds that are missing feathers when it comes to cold winter nights. If you have a bird in a severe molt like the bird in the below picture, save yourself the effort and just bring her to a more mild location, preferably not fully heated, like a garage or basement, to keep an eye on her until her feathers regrow. As was discussed above, heating a bird during molt is believed to lower the amount of down that bird grows in preparation for winter, and is thus not advised--you just want to take the edge off to the point that she is able to pull through it on her own. A normally molting bird is usually fine in the cold, but a nearly naked molting bird may need this help!
Though I have used sweaters to cover nearly naked hens during severe molts, such
as with Cricket, here, I would never put a sweater on a fully feathered hen!
What is most important is that your birds are healthy and strong going into the winter! Make sure the birds have a complete and balanced feed, adequate shelter, and access to water to help them maintain their health in the cold. Shelter is relatively easy to provide, and so is feed unless you give your birds a fermented or soaked feed, but keeping water available can be difficult in frigid conditions. In many cases, one may be forced to check in every few hours and break ice or replace frozen waterers to make sure water is available. Remembering the safety tips explained above for cords and outlets, you can provide a heated water dish or feed pan that will not add supplemental heat to your coop but allow your birds constant access to food and water. This is generally considered less of a fire risk than supplemental heat, but can still be a fire risk simply as a result of the use of electricity, and so should be implemented with the precautions mentioned above!
On the Topic of Comfort
May 18, 2015: The comfort of the birds in wintertime cold is a topic that has frequently been pointed out to me since writing this article last fall. Because comfort is subjective, and especially since there are no real sources for determining the comfort level of chickens, well, I can only share my experience and observations on the subject.
When a chicken is uncomfortable, it can be hard to tell. Chickens are known to hide symptoms of illness. However, all animals will behave differently when they are in temperatures that are not survivable for them, whether it be too hot or too cold. When a bird is in such a condition, you should be able to tell by their behavior. This could be as subtle as a slightly slowed gait, a limp, or a lowered appetite, or even as obvious as a sluggish, droopy, rough appearance. Different birds behave differently when faced with discomfort, as do we humans. To determine how a bird acts when he or she is not feeling right requires a lot of observation and really knowing the norms of your flock.
Obviously, for most, 'survivability' is not the same as 'comfort', and some might argue that long before they start showing signs of it that these birds are uncomfortable. For me, personally, when I see my birds out and about, facing the winter cold without slowing down, and walking through bloomers-deep snow as if it isn't even there, I feel pretty certainly that they are not in any discomfort. Even on the harshest days that we get here in northern Indiana, when the temps drop to the negative teens and the girls decide to stay inside all day, I don't see them just huddling around, instead dust bathing in their dirt floor or hopping around their perches. If they were uncomfortable, I feel they would more likely be huddled in their coop all day, every day, avoiding going outside at all, and certainly not running around and playing wherever they do decide to spend their day. Most importantly, when my birds are active and healthy and vibrant, just as much as they are any other time of year, I cannot believe they are not thriving just because they have not been provided with supplemental heat. Whether this would be true of the same birds if we lived, say, in the arctic circle is another question entirely.
Others might disagree, and that's okay. After all, this is your flock and what you do with it is ultimately up to you.
I feel, in conclusion, that it is necessary to stress again that what works for one person will not always work for everyone else! When deciding how you maintain your flock, you must take into consideration the things that will affect your birds and their home in particular! How often does it get far into negative temps where you live? What breeds are in your flock that may be sensitive to cold? Have you had problems in previous winters as a result of your husbandry methods? As winter approaches, consider everything and assess how well previous winters went if you have had chickens for that long. In the end, you must make an informed choice and decide what works and does not work for your own birds!
Helpful and Informative Links
Winter Chicken Keeping
Winter Weather Tips
Coop Heat Budgeting
Thoughts on Insulation, Winterizing, and Winter Ventilation
Coop Ventilation (General, year-round ventilation info.)
A Journal of Sorts About Chickens in Arctic Weather
Fire Safety in your Coop and Barn
Boredom Busters - Toys for Chickens, Flock Block Recipies (Recipe 1, Recipe 2), Busting Boredom in Winter
Questions? Comments? Suggestions?
I am happy to hear any suggestions and answer any questions in relation to this page, especially if it is something that can improve the information on the page! Please PM me with thoughts on changes, corrections, absolutely anything! Thank you for reading!
Cold Weather Advisory: A Detailed Look at the Question of Supplemental Heat
To make a comment simply sign up and become a member!
Page 1 of 3
Page 1 of 3