Here is a good article, tips on dealing with heat intolerance when you have MS. This is a particular problem for me.
Hot baths are out, and I so loved to soak and read a book. Also shopping in winter, wearing my winter coat inside is an issue. But then the biggie, the heat and humidity of summer. It's the end of May and already we've had a week of higher than normal temperatures.
I hate that the heat bothers me so much. I sometimes feel like a prisoner in my own home, as all my MS symptoms worsen when I get overheated, so I stay indoors and out of the sun.
Stay cool, and stay safe.