You know best how you feel!
Just because it says in some textbook you’re supposed to feel worse in heat doesn’t make it true. If you don’t, then you don’t. I don’t either - so far. Trust your own judgement, and don’t let anyone try to tell you how you feel is wrong.
We all react to this illness in different ways. It’s not possible to generalise that everyone is worse in heat. I know I’m much worse in cold, and this direst, coldest Spring for years has done nothing for me. I’m sure I’d pick up if I went somewhere warmer and sunnier, too - but especially drier.
Funny, when I saw a traditional Chinese acupuncturist (he wasn’t Chinese, but did follow traditional, not modern, acupuncture theories), he said ancient Chinese medicine does not recognize MS as a diagnosis (because it wasn’t understood and labelled until relatively modern times).
Instead, it treats all ailments as due to some kind of imbalance between the elements. In my case, it was an excess of damp.
I know this sounds mad, but he wasn’t denying the modern, Western diagnosis, but just choosing to look at things in an alternative way.
Although I have mixed views about acupuncture generally (I gave up in the end, because I couldn’t persuade myself it was helping), I DO find myself able to relate to the “damp” verdict. Someone suffering from an excess of damp will feel worse in cool, damp places, and in damp weather. I can confirm I particularly dislike damp, mist, and drizzle. I always feel worse in that kind of weather. And I don’t just mean psychologically, because it’s miserable. I find all my pains play up, and the cramps and spasticity worsen. I’ve felt a bit better the last couple of days - drier and sunnier.
I bet if I kept a diary relating symptoms to weather, I’d often see this pattern.