Do not use a heat lamp to warm up the penis. It will help bring blood into the penis but it will not help stop some of the problems associated with pumping.
The only thing I found that help stop the problems associated with pumping is Wet heat “hot water” Soak a rag in hot water and then wrap the hot wet rag around your penis.
That is the only thing I found to help combat most if not all the problems associated with pumping.