During the cold winter months from November to April, desert Tortoises hibernate. Females begin and end hibernating earlier than male tortoises and juveniles generally wake up before the adults. Imagine, several weeks run rampant with juvies. Tortoise activity depends on temperature. While they can survive freezing temps, they are only active when the sun warms the surface up to about 70-90 degrees F. They like to wake up late in the morning, and spend most of their day under shelter. A day of heavy activity may see a tortoise travel a whopping 200 meters.