Random Worldbuilding Questions (Biology, Geography, Society, etc.)

[Ksheep]

3. a similar compound channels heat inward when your temperature is low, and outward when your temperature is high, replacing sweat as a means of regulating temperature.

I'd like to throw in my two cents here, although I am a little late on answering this…

For a mechanism that regulates body heat without sweat, I'd suggest you look at jackrabbits. They have an ingenious solution to this problem… they use their ears. Jackrabbits have rather large ears, which they use as radiators to rid themselves of excess body heat. When they are overheating, the blood vessels in their ears expand, increasing blood flow, which directs their heat toward these areas with large surface area where the heat dissipates quickly. When they need to store heat, said blood vessels contract, keeping blood flow, and thus heat flow, to a minimum.

I believe that other mammals have similar tactics, such as elephants, although I'm not entirely sure…