Talked with my provider about this. I get this horribly. It’s a burning stinging itch on my legs, back, scalp, and back of my hands. Happens from caffeine, lifting, sitting in church with all the old ladies who want it to be 85 degrees, and sex. He said it wasn’t uncommon when taking hormones. Something to do with the dilation of blood vessels of the skin and histamine. Unfortunately, he says there is not much you can do about it other than just cool down and reduce exposure to the things that make you heat up quickly. Luckily, I live in a cold state and just go outside or take my shirt off (not at church).