A person, usually on a construction site, who refuses to dress warmly in cold weather, and will only wear a t-shirt year round.
* Rusty walks by in a t shirt in -5 degree weather *

Mike: Hey, did you see rusty walk by in a t-shirt?

Lyle: Ya, I geuss he's the last of the fresh air boys

This can also can be used as a question to make fun of someone under-dressed...

* Two Dummies walks by in t-shirts *

Darren: Oh, you like that fresh air, boys?
by Fresh air boy February 4, 2010
Get the Fresh air boy mug.