I live near the beach (FL), but I won't brew with sandals on. I burned my toes once wearing regular running shoes and socks. I splashed some hot water (180F) by accident out of the brew kettle during transfer and I've never taken my shoes off faster.
I like the idea of any closed toe shoe/boot. I'd rather have my feet sweaty than burned. Been there, done that.
Your experience may vary. Mr Murphy always seems to brew with me. And my insurance isn't necessarily as good as yours!