I will begin this with a piece of advice about sleeping in a hot room, since it's summer
where I am it is unbearable even with a fan going, so this is one weirde olde tip that I've discovered
what you'll need is a winter beanie-type hat, the heavier the material the better. soak it in cold water, and go to bed wearing it
with a fan blowing on you, it will keep you cool long enough for you to fall asleep. we radiate a lot of our heat through the head.
it's important for the hat material is heavy, so it holds a lot of moisture, and not too porous, or it will dry out too fast. artificial fleece works well