I understand that it’s rude to throw cold water on a popular myth, but c’mon.
That mist you sometimes see rising from a lineman’s head is not steam like the steam rising from boiling water in a kettle. It’s more like mist rising from a pond.
Peace,
mangeorge
Actually, you can’t see steam, which is an invisible gas.
I hope I beat all you physicists to the punch. 
I was a linebacker in High School, so I speak authoritatively on the subject. It’s not steam, and it’s not mist. It’s smoke (from hard thinkin’).
You’re welcome.
When I got off my bike this morning at my local breakfast spot and took off my helmet, mist began rising.
It’s not steam. It’s not condensation. It’s pure Essence Of Sexual Energy and if it didn’t evaporate that way every woman in the vicinity would swoon when they got within 20 yards.
Oh yeah? It’s a known fact that bike riding causes impotence.
Hence the need to discharge the sexual essence as quickly as possible before undue female attention is called!
Win, you already got the boot once for talking dirty. 