One of the most essential ingredients in successful wild-animal housing is a source of heat. As Spas says, next to silence and darkness, warmth is the most important need of wild animals suffering from the stress of temporary captivity. The heating pad is a staple of the wildlife rehabber, although many shelters also use infra-red heat lamps and incubators from time to time. The heating source should never be placed inside the box or cage. Instead, position the heat source outside and at one end of the enclosure so that the animal can move away from the heat after she is warm enough.
Many shelters place thermometers on or near the box or cage to monitor the temperature.
A Return to the Wild Caring for wildlife even temporarily requires an investment in resources and, above all, know-how. That's why, for many shelter workers, it can be frustrating to invest so much energy in stabilizing a wild animal only to say goodbye to the animal within the day. But moving wild animals out of your shelter quickly is essential to their long-term prospects. That's why your shelter should only serve as a way station for injured or orphaned wildlife. Staff should start making those calls to your shelter's network of wildlife experts as soon as possible after the animal is accepted.