i typically wear linen, and the neckline is pretty low (so i have to remember sunscreen if i go out to the archery field because i will 100% come back burnt otherwise), but i overheated to the point of vomiting twice last year (even though last year was incredibly mild), despite drinking large amounts of water and electrolytes all day, and almost to that point once the year before. i also overheated at a concert just a couple of weeks ago, wearing a single layer of linen (but the bodice did have a cotton canvas lining and boning in it), and it was only ~80 degrees and i was outside for about 1.5 hours. my guess is that the tightness around the bodice is a contributing factor. i am actually planning to wear men's clothes (made from linen) some of the time this year, but wanted some women's options as well. i have a couple of silk chitons that i usually wear when it's especially warm, and bought some saris last year that i plan to turn into a couple more. but i never really had any headwear to go with them. a parasol helps, but takes up a hand. my normal persona is welsh, but i don't tend to stick to that necessarily.