When I stand after walking for awhile my knees become very hot. This wouldn't be too much of an issue on its own it's more of an annoyance than anything, but the skin on my legs is sensitive to heat. This causes redness on my legs when exposed to heat, and it creates a rash like redness but it is not inflamed or bumpy. It goes away gradually after about 10 minutes when the heat isnt coming from my knees. The redness appears in the same pattern every time and can even appear from constant sunlight on the area. I'm just wondering what may be causing the redness and my heated joints.