Oh man, I'm a veteran at this.
Get a shallow pan, like a baking pan for brownies, fill to the rim with ice, place on table level with you and aim a fan so that it's blowing over the ice. I made it through 5 days in August once like this after lightning fried the central A/C unit.
An old-fashioned ice bag on the back of the neck also helps. Or save the ice bag for your feet and get a
Chillow. I've seen them as low as $17.99 online. If your feet & the back of your neck are cool, the rest of you will feel cool as well.
Also, go to Target and get the cheapest plain bedsheets you can find; usually under $20 bucks for a full-size set. They will be very thin and rather stiff, thus they will stand away from your skin instead of draping snugly, which traps heat. Learned this from my grandmother, though I'm not going to starch & iron sheets in the summer like she did.