Hello everyone, I am posting on this community to solicit advice on avoiding heat stroke while not looking like a fool. Currently I own several 95% polyester 5% spandex short-sleeve button-ups as well as one 100% linen long-sleeve button-up. I find both to be quite suitable for hot weather, but would love suggestions that aren't T-shirts and button-ups. Additionally, what options are there for summer pants? And what actually looks good with shorts? When I wear them I look like a camp councilor - or worse, a kid attending summer camp. 
Feel free to discuss dresses and skirts as well, although I am personally not interested. Oh yes, and I suppose summer hats could be useful too. Thank you in advance.
I live in a modestly humid climate where temps above 45C are not unheard of and a week above 40C happens once every couple of years. I have a bit of a cottagecore vibe too so my clothing recs tend to loose and slightly formal in summer, but a maxi-dress is out so...
Do not wear the artificial fabrics above 30C. Cotton is fine until wet (and sometimes the temp can plummet below 20 in the evening and it'll feel like -5C, so you don't want that.) In the unlikely event you find a true summerweight wool (like, thin enough to make a peasant blouse out of), it's even better than linen. Linen pants are good for masc types, and in resort wear you can commit to the loose split skirt/culotte style. Try linen waistcoats without shirts or with very thin sheer shirts. Loose cotton short robes/jackets as wellKeep clothing loose and long because the sun is not your friend. Short shorts are in for mascs but in truly hot weather they're not great.
Straw hats only, for men you might be limited to the dreaded fedora, but honestly if you can pull it off a wide brimmed fem hat looks good.
Thanks for the thorough response!