I see you are from Montreal. Try doing a outdoor summer gig in Sacramento.... 100F to 110F in the shade....no breeze, and a blacktop parking lot behind the stage that heats up to 120F.
If I wasn't a fat ass I'd go shirtless too.
Just because I'm from Montreal, what makes you think I do ALL my gigs here?
Believe me, I've been in pretty much every situation possible.
How long are your festival sets? Mine range from 60 to 90 minutes. If you play blues and can't put on some nice cotton pants for that short amount of time then that's your choice. When it's 120F out there, you're cooking in shorts anyway... so why not look good?