There are many kinds out there. I would definitely recommend having one, especially for those super hot days. Some require AA batteries, but there are rechargeable ones with a USB-C cable.
Even pillows have gotten summer ready with their cooling gel technology. These actually come in quite handy as there are a lot of people out there who like to stay cool when they sleep.
These towels are the best. They dry instantly and are supercooling. I would say another essential thing to have with you after the misting fan for scorching summer days.
Even if you have the AC at home, you also need to make sure your sheets are cooling. These bamboo sheets are perfect for the summer so you won't be sweating under the sheets.
I know these are a hit or miss, but I have to be honest it does feel amazing on the skin when it's really hot out and you're sweating. Plus, it goes very nicely on top of an SPF since it's just water.