For warm-blooded animals (endothermic animals), the equivalent term is "estivate". Estivation is a state of reduced activity and metabolic depression that some warm-blooded animals enter during hot and dry seasons when food and water are scarce. It helps them survive extreme temperatures and conserve water. Unlike hibernation, which occurs during winter, estivation takes place during summer or periods of drought. Animals that estivate include certain desert-dwelling mammals, birds, reptiles, and amphibians.