Wear a cooling vest. I got mine at no cost from an MS organization.
Freeze water bottles and drink them while you get dressed and or when you exercise. Or drink water with lots of ice in while you get dressed.
If you consistently exercise your body will get used to it. Your body is going to protest perhaps for months but God made our bodies to adapt to stress. One day you will find that your level of discomfort has decreased. The benefits that you will achieve will far outweigh the discomfort that you will experience in the beginning. I have exercised thru three relapses so far.
You could also buy one of those battery powered fans. They range in sizes and can be found in discount stores like Wal Mart, Dollar General, Family Dollar, etc.

Also, I buy a lot of tops with holes in them. I have found tops in which my entire back is out. I bought them from a store called Forever 21. Also in Wal Mart and Target and any store that sells active clothing, they sell clothing that has wicking fabric. That means the fabric absorbs moisture and you stay cooler. I NEVER WEAR TSHIRTS WHEN EXERCISING. THAT WOULD BE THE KISS OF DEATH FOR ME. LOL.

I will take some photos of my holey tops, if you want. I am always buying them.

Not sure what you do for exercise, but I have been told to do water exercise cause it keeps you cool

Check out my blog. I posted about heat intolerance. http://jenndsblog.blogspot.com/2014/07/truth-ab...

I make sure I have a fan plugged in and pointing right at me while I exercise. I also take a lot of drinks of water with ice while I'm exercising. I usually wear a tank top and shorts because I get too hot in t-shirts.

I wear Frog Toggs, around my wrists and neck. Run them under cold water and put them on. They assist in evaporation and keep me cool while working out.