While it is true that hamsters coats may change a little bit to compensate for the colder air, their coats do not thicken up as much as a dog or cat's will. Winter White hamsters have fur that changes white in the winter to help camouflage them in the snow (Although this will not happen to indoor Winter Whites, as the temperatures in you house won't be cold enough and the use of unnatural light masks the flow of time for the furry little things.)
So how do they keep warm?
Hamsters are complicated little balls of fluff, and believe it or not they stay warm the same ways that we do! No they don't wear jackets! (Although that would be adorable!) They hide in their little houses, and they pack on the pounds!
How can I make sure my ham ham warm enough?
The same way you keep yourself warm!
When your cold you dig out extra blankets right? Well your hammie will do the same! Put extra bedding in your hamster's habitat. They will thank you for the extra nesting materials! Also, consider putting shredded toilet paper in there home as well. Paper insulates heat and is soft and comfey. If your hamster does not have a little house to hide in you should get one.
Turn on a heater! That's how you keep yourself warm isn't it? Just make sure you do not direct the heater too close to the hamster's cage, because he or she may get too hot. If possible just move them to a warmer room in the house. Heat lamps will also work well but your hammie might not like the constant light. Many people say to place a heating pad under the cage but I do NOT recommend doing this as the bottom of the cage can get much too hot for their little feet. (And in the case of cages with plastic bases they can melt!)
Let them pack on the pounds! Give them a little extra food. Fuller tummies help us all feel warmer!
Keep them away from windows, door and drafts. The wind can cause chills. You can cover part of the cage to prevent drafts.
*Wired/plastic cages: Make sure you do not do this with a towel or blanket, as your furry little friend will pull the material in through the bars and chew it. This is unsafe as they can get caught in the threads, choke on them, or die from trying to ingest them. For this type of cage, I recommend using pieces of cardboard (This is what I do for Sasha, aside from extra nesting materials and keeping her in a warmer room).
*Tanks: Preventing drafts for a small animal in a tank is much easier. Since only the top of the tank is exposed to drafts you can easily drape a blanket or towel over half of the cage, and presto! Your done! You can use a blanket or towel this time because the openings on the wire mesh screen for the tank will be too small to pull fabric through.
Keep them in doors at all times! This should go without saying because hamsters are not outside pets! If you have to transport them somewhere, like for a vet visit, make sure their carrier is well protected from the wind and give them plenty of bedding and shredded toiled paper to nest in.
Won't they hibernate?
No! Hamsters are not bears! Although if they get too cold, they will fall into a state called Torpor. Hamsters originated in climates that were typically warm in the day, and cold in the night, so their tiny bodies can compensate for some temperature fluctuations. But if the temperature drops below 40 degrees Fahrenheit, they may fall into a temporary state of hibernation called Torpor. A hamster in Torpor will build a warm nest, eat as much as they can, and bed down and sleep to conserve energy and stay warm. In small animals this usually only lasts a few hours (Not longer than a day). Hamsters in this state may appear lifeless, but upon close observation will have shallow breathing and twitching whiskers. They will be rather unresponsive but should be woken up immediately, but GENTLY. To wake a hamster in Torpor you should gently nuzzle them, and warm them. Once a hamster wakes from Torpor it may be groggy and grumpy, so move him or her to a warmer area, give them plenty of food and leave them alone for a bit. If they do not resume normal activities within a day or two, you should consult a vet.
In short keep your ham hams warm! :)) I hope everyone is having a wonderful winter and keeping both themselves and their pets warm.