Is there a type of medication or treatment that a person can take who quits sweating after he gets hot?

Answer 1

Yes there is treatment available from your Doctor if you have a medical disorder. Make sure that you have verified lack of sweat is caused by either lack of sweat glands, or hormones the doctor will help with that.
If you have no medical condition causing it, then do drink lots of water, lots! not sports drinks etc. Also cool yourself off with wet towels, or wet cloths around your neck or head.

Also decrease your salt intake as that causes water retention.

Answer 2

Sure!
It's called DRINK MORE WATER>