Reddit mentions of Juniper UV 50+ Side Mesh Talson Bucket Hat - Khaki

Seersucker was invented in India because the way it's woven, it stands out a little from the body and lets a little breeze in. Consider men's seersucker clothing if you're female and can't find any loose-fitting seersucker.

Also consider a men's guayabera -- these are what men wear in Latin America, untucked, with lots of pockets, lots of room for cooling breezes, and looks dressy enough to go anywhere.

If you get desperate you can upend a canteen of water over your head and your seersucker or guayabera too. Just remove electronics first.

Here is the kind of hat everyone wears in Arizona and New Mexico. It has a mesh cutout so a little breeze can get in. https://www.amazon.com/Side-Mesh-Talson-Bucket-Hat/dp/B0080I9OYW If you have long hair, that chin tie can be fixed to keep the hair up off your neck.

As others have suggested, I like khaki cargo shorts, but if you can find any seersucker shorts great.

I also wear men's Hawaiian shirts--again, cotton (sometimes silk), big and breezy and look good untucked.

I can't say enough good about Duofold Varitec. I have to check to make sure I'm even wearing a shirt when I go out in this fabric. Again, it's been easier for me to find them in Men's.

Edited to add: I prefer athletic sandals (again, I buy men's because I can't find a single pair in women's that aren't all kinds of crazy turquoise and orange colors) https://www.kohls.com/product/prd-2721482/croft-barrow-mens-bungee-fisherman-sandals.jsp?ci_mcc=ci&utm_campaign=MENS%20DRESS/CAS%20SHOES&utm_medium=CSE&utm_source=google&utm_product=73525577&CID=shopping15&utm_campaignid=196833692&gclid=EAIaIQobChMIp-bw3Iyl1QIVU1YNCh3--ws4EAQYBSABEgJd4fD_BwE&gclsrc=aw.ds&dclid=COPwouCMpdUCFY0PgQodsFEB4w

In Arizona they advise against any kind of sandal, but it's not hot enough in KC to burn your sandals up like it is in Phoenix. Not kidding, in Phoenix my sneaker bottoms melted to the asphalt and came off. Anyway I have found athletic sandals with good arch support to stand up to the heat and walking just fine.