It looks very plausible that stretching before you exercise doesn’t do much for you. Multiple older surveys suggested this.
Annoyingly, the studies linked in the previous paragraph are 2 decades old, and somehow I can’t find a large, well controlled, trial.
you’re not wrong. a lot of the places I’ve been to have different temp classes - when I first started I’d do the 105° classes but there have been plenty of times I needed to step out and take a break to cool off.
last place I used to go to had 95° classes that were more fitness/strength focused, and that was definitely my sweet spot. plus, nothing prepares you for running in the heat like holding a plank in a hot room.