we might end up becoming a nocturnal + crepuscular species, sleeping through the hot days and working through the slightly less hot nights, get our sunlight doses at dawn/dusk
any reason this can't happen biologically speaking?
Interrupted sleep is also supposed to be our natural state in winter (or so I read somewhere). Two stretches of sleep overnight with an interruption in between, and a nap in the afternoon.
I love my sun and vitamin D though, so I don't think I'd want to become nocturnal...
Also, I think we do require low-ish temperatures for proper sleep (like 15 to 20 C?), so sleeping during the hot times probably wouldn't work that well