Syrian Hamsters can hibernate when there is a sudden change in their environment ie sudden temperature drop, lack of water, etc. A hibernating hamster may appear stiff and cold with little evidence of breathing and many owners have assumed a hibernating hamster to be dead at first.
Careful observation will reveal that the whiskers continue to twitch at intervals if the hamster is hibernating. Due to the fact that hamsters do not 'plan' to hibernate but it is induced by a sudden environment change they should be roused to avoid dehydration and starvation.
The hamster should be placed in a warm room or the temperature of the room increased slightly. The hamster should not be placed near a fire or on a radiator or anywhere in extreme heat. As the hamster begins to rouse the hamster will start to shake and tremble, the body temperature will gradually rise and the twitching of the whiskers will increase. Full arousal from hibernation can often take between 30 and 60 minutes.
Once the hamster is active plenty of food and water should be available and the hamster should be left quietly.
Dwarf Hamsters deal much better with colder temperatures than Syrian Hamsters and are not known to hibernate.