I am 33 and in good health. (5' 11" 185 lbs)
I have never had any health problems, nor have I ever had any problems with my feet.
About a week ago, I noticed a very warm sensation in the arch of my left foot.
It doesn't hurt at all; it just feels like I have my foot close to a heat source.
The first time, I actually looked under my computer desk to make sure that the power strip wasn't overheating.
The sensation occurs every 15 minutes or so, but sometimes I'll go for a few hours without experiencing it at all.
I wear steel toe boots every day and have been wearing my current pair for about 3 months.
Any ideas?