Ive bought 6 of these from eBay for a quid (uk based sellers might cost more) they’re also known as sports towels, and I’ve given a couple to my sisters for the menopause!
Used dry they wipe off sweat, but run one under the cold tap for 5 seconds, squeeze out the dripping water and you’ve got an ice towel! Wear it round your neck, drape it round your bare shoulders, or wrap it like a turban and you’ve got instant relief, (don’t wrap your head if you’ve got good hair it’ll ruin it) when it warms up a bit remove it shake it for 5 seconds and it’s cold again.
I must admit I was sceptical until I tried one wet, I was so impressed I bought 5 more. They come in pink, blue, heather and I’m sure I saw some in other colours. I’m actually thinking about buying some more, they work well enough for me (the biggest heat moaner/loather) it’s not sunshine I hate it’s heat!