Why do I get itchy all the time?

This has been happening to me a tooooon.
I’ll be in a…moderately warm area, pleasant really, and my skin will just start crawling. It’s horrible and unbearable, I can’t concentrate on anything but getting cool again. I had to run outside into the freezing cold a few times today because of this.
It also tends to happen when I have a good laugh.
I’m pretty sure it’s just me sweating, and having dry skin from winter, so I guess a good answer, aside from “it’s not because you’re dry” would be to offer an alternative solution to getting rid of the itches!