How to stay cool without AC
stay hydrated - it doesn’t matter what the water temp is, sometimes room temp or slightly cool is better than cold
stay on the lowest level of the house
close the doors of unused rooms that do not have vents, you are cooling down less space
wear breathable fabrics - linen and cotton
close blinds and curtains to keep the sun from heating up the inside of rooms
box fans - try to get cross ventilation, even if you have a little fan it will help to have one near you
take a shower or a bath - cool if possible but not cold
cook with a slow cooker/toaster oven or use stove and oven only in the morning
use cold washcloths on your neck and wrists to cool down - but don’t chill/freeze clothing or blankets, they can become damp and then cause mold problems.
check your area for public cooling centers
(if you have AC, don’t go below 70 degrees F, this puts more strain on the unit and doesn’t lower the temps inside any sooner, keep the thermostat at the highest comfortable setting)