As a poor person, maybe most useful advice for other poor people is water bottles. Tap water is colder than the air so I try to keep a plastic water bottle in my hand or pressed against my skin and it helps a lot.
If anyone is in a bind, post your situation and we/I will try to come up with a simple enough solution. My irl qualifications might be useful for the first time online lol: I was homeless for 2 months and have been poor af for my whole life, so i’ve had to ghetto innovate a lot of stuff.
Along these same lines, cooling towels are long, thin towels. Wet them down and place them around the nape of your neck for a surprisingly strong cooling effect. They can also be placed in the freezer.