Question

How does ur body maintain constant tempature on a hot day?

Answer 1

It knows that when water evaporates, it carries heat energy away with it. 
So your body puts some water out on your skin, and hopes that it will
evaporate.  We call that "perspiring" or "sweating".

Answer 2

Answer:

your skin opens up

Explanation:

the pores i your skin opens up and let the water (sweat) out to help cool down your body.