Heat causing uncomfortable bloating ?

I’ve had a bunch of new symptoms emerge in the last 2 years (been sick for 10). One of them is immediately bloating like a balloon when I start overheating and it snowballs into having horrible nausea and shortness of breath. It doesn’t even have to be all that hot. The only thing that helps these episodes is dumping cold water on myself or standing directly in front of the AC. But it takes about half an hour to get back to normal. I just don’t know why I’m having so many change in symptoms, it’s scaring me a little.