How was this decided?

[debid]

If you're using an infrared bulb, that heats objects, not air. A thermometer measures air temp. So, you won't get an accurate measurement of how much your bulb heats the chicks.

I didn't use a thermometer when I used bulbs and I honestly think trying to measure causes more trouble than it's worth for most folks. Instead, I watched the chicks and adjusted the setup as needed. Then, I found the mama heating pad thread and retired the bulbs.

 

[rosemarythyme]

I used the guidelines as a starting point, then after that watched the behavior of the chicks instead of looking at a thermometer. I figure that's the best way to judge if the temperature is too low or high, instead of following a formula as if I was baking a cake.

 

[azygous]

Those brooder heat guidelines bug me no end. And don't even get me started on how useless the help is in feed stores that are selling most of the chicks people buy. They mostly want to sell accessories like those cute but useless coops and "brooding kits" consisting of 250 watt food warming lights.

I remember when I got my very first chicks about this time of year nine years ago. I didn't have a clue. I got my chicks off an ad on Craig's List where someone was selling some surplus Light Brahmas they'd ordered. They were already three weeks old, but I was told about the heat "rules" nonetheless.

I didn't understand why and it would have helped. I had no idea what was supposed to happen if the "rules" weren't followed or how much leeway there was. I didn't know about BYC yet, so I had nowhere to find out, so I followed the rules. I imagine so many new chick owners are in the same boat.

The heat guidelines should stress that the temperatures are merely a starting point and that there are lots of variables that need to be considered along with them. The ambient temperature, where the brooder is located, how large the brooder is, the material the brooder is made from, how many chicks are being brooded, and age of the chicks. All of these factors affect how warm the heat source will need to be.

And no one includes helpful information with the guidelines such as chicks needing cool zones to shed excess heat. Chickens are related to reptiles and during the first month they regulate their body temps much the same as lizards and snakes by moving in and out of warm and cool zones as needed.

The guidelines say to reduce the temperature by five degrees each week, but they don't say it's because as chicks grow in real feathers to replace the down, they don't need as much heat because they aren't losing as much body heat. And the most important of all, that by the time they're a month old, they have grown enough feather covering to reach a point of equilibrium. Their caloric intake combined with the insulating effect of their feathers is enough to keep their temperature regulated, and it's time to ditch the heat source soon.

So often on this forum I run across posts asking when it's okay to remove the heat lamp, and the "chicks" are ten weeks old. I think it would be a splendid idea to put a tag with https://www.backyardchickens.com on every chick sold.