I've had them, intense heat but not 'just hot' kind of heat, I can't quick explain it.

when I get them, I feel an intense heat inside my body and it stays for minutes on end.
Around 3am the other morning, I awoke burning up, it felt like I had a very high temperature and stayed like this for some time, the intense heat was so hot it woke me up. Still can't explain it and gave it no thought till I read your thread,

thanks for posting