I have a foot condition that devloped overnight on the upper outside of my foot about halfway between my ankle and first joint of my little toe. It is a very pronounced knot that is red on the surface, warm to touch, and VERY sensitive. At first I thought it was gout since this is the second time in a couple of months that I've had this problem. I have tried to apply heat but this makes the pain worse.

Could also have been prompted from sitting cross-legged on the floor?

Whatever is it..it hurts like h###. Anybody got any idea what's causing this?

I can't tell you what may be causeing your pain, but I'd get it checked by a doctor. In the mean time use Ice, not heat. Ice will reduce swelling and help with pain. Don't leave it on for more than 20 mins at a time though. good luck