I'm a Midwest factory worker, so my coping strategies might help.
Those evporatuon towels? A scam. They are no better than a wet bandana or other small thin piece of cloth. Forget about that shit.
What you need is ice. Get a big cooler and a bunch of big water bottles and fill the bottles with ice water. Plan to drink about 32oz an hour, by the time your bottle is empty all the ice will probably have melted so don't worry about that. Then hot swap to a new bottle and keep drinking.
Don't eat less than 2 hours before work, skip lunch, and eat most of your calories after work. At work all you need are electrolytes, digestion generates heat so avoid anything your body has to work on. I have a little bottle of electrolyte tablets on me and have one every 64oz.
Wearable fans kind of help? Not a lot, but every little bit can be a life saver.
And dress as light as you're allowed. If you're allowed to wear leggings, do that. If it has to be jeans, get something well fitted so there is as little air between your legs and the fabric as possible. Sometimes stretchy jeans are allowed even if leggings aren't, so look into that too.
And... I think that's all the wisdom I have to impart from my experiences? In the Midwest it's not humid ALL the time so I carry a spray bottle to spritz myself with, but when it's humid that shit don't work lol