I have noticed that the areas on me that are most padded also turn blotchy red/purple after I finish my ride. I don't notice it while I'm still riding. It can happen to me with temps below 48F.

I assume it is because the fat insulates the skin from the warmer core; and the surface blood vessels constrict to keep the core warmer.

It is itchy but I don't think it causes any problems if it's back to normal within an hour.

Thanks for making this post - none of the other people I ride with have this happen to them, so I've just tried to figure it out on my own.