A vertebrate is considered cold-blooded if its internal body temperature matches the external temperature around it. Fish , amphibians and reptiles are examples of cold-blooded animals. Their dependence on the water or land makes it necessary for them to adapt to the temperature surrounding them. No matter what the temperature is outside, their internal body temperature remains the same. Only birds and mammals are warm-blooded.
Birds rely upon their feathers to help adapt to temperature changes.
Birdlist A Pigeon Inquiry Banana-Pusher American Birding Mammals rely upon skin, hair, or fur to help adapt to temperature changes. Another characteristic of all mammals is the ability of the female to produce milk to feed her babies. Some mammals, like whales, live in the water and must adapt to changing water temperatures. Other land mammals, like wolves, have adapted to very cold climates. In general, however, warm-blooded animals must prepare for temperature extremes in order to survive.