What Causes Warmness In The Body?

Hi, im a male, 28 years old old, 6'1-6'2 about 188lbs. The problem i seem to be having is that sometimes my skin will feel warm or hot but i never have a fever or high blood pressure. It seems to come up the most in the evenings instead of during the day but it can also happen during the day too. Also, it comes and goes and sometimes lasts for a couple of days. For instance i could be fine for a week and then feel like that for 3 days, but each feeling varies in length. I never sweat though, even in bed. I've never had any major medical issues except a-fib, but that was treated and everything is ok in that department now. This just started happening a few months ago.