Whenever i get hot i get red patches on my back, chest, and stomach that's itchy and burns and it keeps getting worse. what could this be?

Angioedema: Allergic reactions of hives and angioedema can occur in certain people exposed to heat or cold environments. For relief, antihistamines such as benadryl(causes drowsiness)or claritin(doesn't cause drowsiness) can be used. An allergist can give you more information and help.

Hard to say: Without seeing it. Could be hives or other rash. Could be an allergic reaction or a rash that just comes for a reason no one knows. Try zyrtec, (cetirizine) store brand is fine, once a day, Saran lotion for itching as much as you want, and stay away from hot showers . Try to figure out triggers so you can avoid the rash if possible. You will probably need the help of a doc.