I had this problem living in Dallas: it'll hit 108°F just about every day this week.

I also couldn't spend thousands on an energy recovery ventilator (ERV) installation because I've been living in rental properties.

My solution was to buy an ERV for ~$500 and rig it up to an open window: https://gen.co/air

I've since moved into a condo with a bedroom with no windows and french glass doors so I installed a cat door and mounted the ERV vents to that.

I think there's a lot of money here for someone to build an ERV designed to be window mounted.

Simplest solution is a high efficiency air to air heat exchanger to let you circulate a lot of outside air. They are less efficient when dealing with high humidity, but you can have this as part of your HVAC system and never really think about it.

https://en.wikipedia.org/wiki/Heat_recovery_ventilation

Interesting problem. Mind sharing roughly where that is?