Some time ago I read an article on hot water bottles as personal heating/cooling systems, and it's great:
https://solar.lowtechmagazine.com/2022/01/the-revenge-of-the-hot-water-bottle.html
Since the I bought one, and in hot weather I store it in the freezer / refrigerator (for those that have one)
Also, water cools when it evaporates, so a spray bottle and a hand or electric fan is an amazing combo: spray your face and the fan multiplies the effect.