July was the hottest month I can remember, and it taught me what actually works in the heat. Most of it is common sense. The rest is a very good hat.
What I wore on repeat
Loose linen shirts in pale colours, one pair of wide cotton trousers, leather sandals that do not rub, and a straw hat wide enough to shade my shoulders. That was almost all of it.
I left synthetic fabrics and anything tight in the cupboard. They are fine in September. In July, they are a punishment.