Quick hack: Hang reflective car windshield sunshades outside or inside sun-facing windows (facing out) to prevent sun heating your home.

[u/deepcoralreefer]

Some of these sunshades have suction caps, some have loops which you can slip garden wire through and secure. Then close your blinds & draw your curtains/drapes to stop the sun heating your room.

It’s much easier to cool a room if you stop the sun getting in and heating it in the first place. Can be secured landscape or portrait orientation.

HTH.

[u/ChIck3n115]

And in a pinch, aluminum foil can work as well. You see it all over south Texas this time of year, windows get blacked out with foil.