[DrKMcK]

I just went online and found this explaination. I hope this helps.

Do hamsters hibernate: No!! Hamsters are not true hibernators. Hamsters like to be in the range of 65 75 degree Fahrenheit. If the temperature drops below 40 degrees Fahrenheit they may go into a temporary hibernating state. This temporary hibernating state is called torpor: Torpor is a form of dormancy that is very similar to hibernation. But the difference between hibernation and torpor is how long the animals sleep times vary and how much the animal's bodies slow down. Torpor is a state of regulated hypothermia in an Endotherm: An Endotherm is an animal that is capable of maintaining its body temperature above the temperature of the external environment. Torpor may last just a few hours but usually no more than a day. Some mammals that live through cold periods when food is hard to find especially very small mammals have the ability to let their body temperature drop. Hamsters can go into this hibernating state and they have retained the ability to do so in captivity.
A true hibernation is a state of dormancy that allows an animal to conserve energy during the winter months when food is in short supply. During hibernation animals slow their metabolism to a very low level, this allow them to use their energy reserves stored as body fat at a much slower rate.
What does a hamster look like when hibernating

What does a hamster look like when hibernating? If you have a hibernating hamster in this sleeping (torpor) state it may appear that all life is extinct in the hamster and it may appear to be life-less (dead). It will not respond to sound, handling or touching. A hibernating hamster will curl up into a ball in the nest, this is to conserve heat in the abdominal region. You will be able to pick the hamster up without him knowing it, and will not wake up on handling. But close observation will reveal the hamster’s whiskers (vibrissae) are still twitching. The hamster still has to breath when in torpor, although very very slowly this can be seen on close observation. The hamster must be aroused by slowly warming and gentle handling and stroking. After the arousal period it may be noted that hamster will be little groggy and trembling this will last only for a very short time.
hibernating hamster

Why do animals hibernate?

Animals that hibernate, or go to sleep temporary (torpor) is to escape the cold and when it is really hard to find food during the winter months. By going into this deep sleep it means the animal is able to survive the cold winter. But before hibernating the animal will eat more food than usual, and this is stored as excess fat. Their bodies will then live off that fat as they sleep through the winter. The animal may appear life less (dead.) During hibernation the animal’s heartbeat and breathing slow down. This is when that stored fat that the animal piled on before the winter comes in handy. This stored fat will last them longer because their bodies slow down so much that they don’t need much energy. This is how the animal can survive through the whole winter on the stored body fat. This is something that hamsters don’t do and therefore the hamster will die of starvation or hypothermia if allowed to continue any length of time in the state of hibernation.

In captivity there is no need for a hamster to hibernate as food and warmth is plentiful. Hamsters in captivity should ‘Not’ be allowed or encouraged to hibernate. To prevent a hamster from hibernating it is suggested to keep your hamster warm. Keep the temperature above 15°C (60°F) and keeping them well lit for at least 12 hours a day. Provide plenty of food and handle regularly. If the temperature drops below 5°C (40° F) they may go into temporary hibernation or dormancy, a torpid state. A hibernating hamster may die of hypothermia or starvation if left in hibernation for any long periods of time.

Keep hamsters warm during the winter months. It may be an idea to leave them in the warmest room of the house if possible. The same room as you normally use during the day and evenings. Give them plenty of nesting material to make them a good size nest. Using a heat lamp above the cage in cold rooms will keep them warm.

Aestivation: or Estivation is another form of dormancy (sleep) similar to hibernation except this is used in the summer to protect the animals from high temperatures and drought and the potentially harmful effects of the season. Some animals aestivate to conserve energy when their food and water supply is low.