Ectotherm

This gecko, whose name is Spike, differs very greatly from humans in the way that he controls his body temperature. Spike is ectothermic, which means that he needs external sources of heat rather than internal sources that humans have in order to regulate his body temperature. For Spike this might mean that on a cold night he might decide to sleep on a warm rock or stay under a heated lamp in order to keep his internal temperature near where it normally is at.