Brian, I tried the foot ones. I thought my toes were on fire! Then they got all sweaty and so my feet were on fire on the bottom of the toes, but sweating all over.
I sometimes do duct tape one inside the cuff of each pant leg of my coveralls. Sitting in the stand with my knees bent, I often get chilled below the knees, not just in the feet either. This helps quite a bit without feeling like my legs are on fire. It also helps stave off my feet feeling as cold.
"If you look through your scope and see your shoe, aim higher."
-- said to me by my 11 year old daughter before going out for hogs 8/13/2011