Tortoise Trust Web - Refrigerator Hibernation for Tortoises and Turtles
Refrigerators have been used successfully to artificially hibernate many animals. Snakes, lizards and even bats have been hibernated in domestic refrigerators. Many tortoise and turtle keepers have also discovered the benefits of this system.
Refrigerators can offer a highly stable temperature in precisely the ideal range for chelonian hibernation, which is generally agreed to be in the 3-5 degree Celsius (37.4 to 41 degrees Fahrenheit) range (depending on species). Even if room temperatures rise to above the level at which tortoises begin to activate and use up more energy (around 10 Celsius or 50 degrees F.) the temperature in the refrigerator will remain at safe levels.
What a refrigerator will NOT DO, however, is protect the animals if external temperatures fall BELOW the desired levels. In other words, just because 5 Celsius is the setting on the refrigerator, if the room temperature falls to -3 degrees, or even -1 degree, the TORTOISES WILL STILL FREEZE TO DEATH. It is therefore ABSOLUTELY ESSENTIAL that refrigerators used for hibernation purposes are situated in a room where above-freezing temperatures are guaranteed. A warm room is fine. A cool room is also fine - but a cold room or garage, or similar, is certainly NOT safe. I would recommend placing the refrigerator in a room that gets NO COLDER THAN 10 Celsius or 50 degrees F. Use a reliable maximum-minimum thermometer to survey the room where the refrigerator is to be placed, and monitor it regularly throughout the hibernation period.
