"Is this considered heat intolerance?" No, unless every time you go to the store its really hot outside, (not just how you feel).
Heat intolerance is when you physically cant take high ambient temperatures as well as others. Lets say you cant take heat above 90F like most other people. It makes you feel sick, dehydrated, weak, faint, ect.
It sounds like what you are experiencing is pre hyper hot feeliog or still adjusting to the higher dose of med.
Post your lab #;'s.