Contrary to what we would expect of reptiles, the leatherback turtle is actually warm-blooded. A. Even though they swim into cold ocean waters, leatherbacks maintain their body heat in much the same way as sea turtles in warm southern oceans do. B. The leatherback turtle uses a countercurrent exchange system in order to keep the flippers from drawing heat away from the rest of the body. C. The shape of the leatherback turtle's flippers is especially important in maintaining heat in extremely cold northern waters. D. The leatherback turtle is able to maintain body heat through sheer size. E. Leatherbacks have an insulating layer that can be considered the reptilian version of blubber. F. Young leatherbacks often do not survive to adulthood because they are not able to switch from a cold-blooded way of life to a warm-blooded one quickly enough.