Depending on what I'm on, I sometimes get the worst muscle cramps while shooting.
For example, imagine using my left hand to shoot 2 cc's into my right side delt. Well, after like 1/2 cc my left bicep starts cramping like crazy and I actually have to let go of the dart, stretch out my arm for a few seconds, and then go back to shooting.
One time, while doing a glute inject of 3 cc's, my hand cramped up. I was shooting through some serious scar tissue and I was pressing pretty hard throughout. Anyhow, after the shot I capped the pin and placed it down on the table but my hand would not release. It was stuck in that "shooting" position for a few seconds.
I think that Tren cramps me up like that...
Oh, and about the sweating - nope, not here.