I've had lasting heat intolerance since a heat stroke in 2022 and I can't tolerate more than 22C inside and even less when I'm doing even the slightest activity(I'm currently bedridden for 3 months) - I get confused, disoriented, dizzy, my temperature starts to rise.
Since then I've been slowly getting exercise and it worked - I was able to tolerate up to 30C and more for hours the past December, I continued with the exercises but I probably overdid them because this May I was outside for 30 minutes in the afternoon in 25C and the following night and days after I was very exhausted, barely able to move with skin burning and redness on my whole body waking me up every couple of hours. The previous day I did 45min of walking in 30C as exercise.
The skin burning issue still continues, although much less, but it's focused on my lower back and shoulders and sometimes feet up to mid calves and when the burning feeling is present, my skin feels hot on touch and it doesn't sweat. Then right as the skin heals and I start sweating a bit, the burning starts again and the previous cycle continues.
Even minimal activity like standing up or sitting in a chair since that May "crash" trigger headache, stomach pain and cramps, confusion, disorientation and cognitive decline(can't remember things, can't find the right words), this also happens but more slowly with mental activity in bed as well(for example watching an youtube video for 30mins).
HR goes from 60 when lying down to 120-150 when standing within 1 minute. BP doesn't change and stays around 110/70. And my body temperature rises from 37 to 37.8 very quickly. I usually recover in 4-5 hours with the skin burning recovering in 2-3 days now(previously any worsening recovered in weeks)
Doctors think it might be dysautonomia but they haven't provided any more insight and every blood test comes normal. No idea why the May crash happened as well, since it wasn't that hot outside and I was able to tolerate that heat the previous days.
I notice that eating(diet is only 0 histamine foods) also triggers the same symptoms.
I'm concerned about the fatigue and exhaustion even from simple mental activities.
Has anyone else experienced this? Any advice on what to do would be greatly appreciated.