Short term while your still looking/finding something. Hang wet towels or sheets over open doorways and windows. Any breeze will be cooled by coming through them.

This is how we used to cool down my mums house before her getting ac in her 1940s built house

We got an air to air one from the good guys years ago in 2009 . My sisters split system broke a couple of weeks ago and she borrowed it. Hadn't been used in ages and it still worked awesomely. It was about 600-700. That was a while ago though.

Maybe have a look on gumtree?

I had a cheap portable air conditioner and i hated it mine didnt work very well and it chewed power. so when i lived in my rental i bought a 2nd hand wall/window style airconditioner for like 80 bucks put it in the sliding window in the lounge room and just boarded off the rest of the window.

It wasnt pretty but omg im so glad i did it made such a difference.

Just an FYI, evaporative coolers don't work at all in humidity, so if your coastal they won't work. If your inland with minimal humidity they work a treat.

Not much help but we bought this cheapie portable "evaporative cooler" from The Good Guys a few years back. I don't think its actually a portable air con unit but you can put water in it. We just use plain tap water and it makes a difference compared to our pedestal fans that just push the hot air around!

Hopefully it means that a proper, good quality portable air conditioner would be even better lol

appliances on line have the best electrical gadgets that's are up to 70% off all legit with warranty and super fast delivery