More of my waterbirth tips: you can get hot in the warm water so drinkn lots of fluids and be prepared that your midwife will be offering you fluid even if you don't feel thirsty. Keep drinking as dehydration = drip = out of the pool.

Also I wore a t-shirt in the water which got wet (obviously), and the part that was above the waterline helped cool me down like a cold flannel that could not fall off. I did this with DS2's birth as my MIL was there and I wasn't ready to be naked in front of her, but it was so lovely I repeated it with the twins. (They were not born in the water, I just laboured in it. See my birth story in my sig for details).