As someone who’s kind of done it all and lived mostly without aircon… What I have found helpful:

• Everything closed up, even doors inside, especially if the sun is on one part of the dwelling, during the day. Keep the doors closed between the hottest rooms if possible.
• Car sunscreens on the window have helped reduced the heat a little.
• Open up windows at night if possible and cooler outside, although sometimes ambient heat make it challenging.
• Portable fan on the body when sleeping. As someone that used to not be able to sleep with the sound of fans, the day I finally could, this was a game changer. It kept me cool enough to sleep.
• A comfortable foam mattress to sleep on the floor of another room if the bedroom is too hot. Heat rises, so it will be cooler closer to the floor. (This I can’t recommend enough. A few nights of restlessness in the heat is enough to make anyone batty.)

I’ve had portable units from evaporators to vented aircons. The cool air from a portable aircon is an amazing, but my unit was noisy as all hell and made it hard to sleep.