Several new chicken folks are talking about hatching eggs they collect in fridgid winter temperatures. This is not the best time of year to be hatching eggs either collected or shipped. I'm thinking their hatch rates will be discouraging so I'm starting this thread with some information gleaned from my 20 plus years of chicken breeding and discussions with some great breeders over the years...Hope this helps improve hatch rates. Please add more cautions and suggestions you have to offer. For those incubating eggs collected during these cold winter temperatures....things to consider... 1) roosters with any frostbite on their combs may not be as fertile until the frostbite heals 2) Freezing temperatures can kill the embryo within an hour of laying unless collected while the hen is still covering the egg. 3) hens use energy and nutrition from digesting feed to stay warm...this can affect the hatching vitality of the embryo in the eggs produced in cold temperatures. The quality of the shell surface is also affected. 4) just as in temperatures over 90 degrees in summer, temps below freezing affect the fertility of your roosters. 5) eggs are 90% fluid...so lack of access to unfrozen water can be harmful to egg production and hatch ability. Collect your eggs frequently during the day. Provide plenty of water during the day...warm water added to a frozen layer helps keep it unfrozen a bit longer. I provide water three times a day in harsh temperature. Using cod liver oil or vasaline on combs during fridgid temperatures...good on legs too...to prevent frostbite. Provide a hard grain treat in the evening so birds can generate warmth by digesting these at night...BOSS, cracked corn, wheat, etc. When incubating...bring eggs to room temperature and then place in the incubator...too quick a change in temperature will cause eggs to sweat or condense on the surface allowing bacteria to grow and draw inside thru the porous shell. To pretreat eggs for bacteria : Use a 10% Oxine spray on the eggs or a 50% Gold Listerine spray and allow eggs to dry before placing in the incubator. Select eggs for hatching that have a quality shell shape and surface Candle eggs before placing in the incubator looking for fine cracks from freezing. Candle at five days and again at 8 days and remove any eggs that are not growing embryos...a burst egg in the incubator is not only messy, but contaminates everything! I will put my breed pens together in late January and begin collecting eggs around the middle of February to incubate. Since hens can lay a clutch of eggs from breeding with a rooster, I like to expose my hens to my chosen cock for at least three weeks before selecting eggs for hatching.