For The Last Few Weeks, I Have Not Been Able

For the last few weeks, I have not been able to tolerate the heat. I'm curious if it could be related to my hypertension.. I'm 64 years so it's not menopause. I also go to the gym 4-5 times a week, and eat fairly healthy
I don't take anything for the hypertension as I have a very bad drug reaction. Meds for the hypertension have caused my hair to fall out, hair on my face to grow, nightmares, and swollen legs, just to name a few. Thanks for any information you can provide.