Your not allowed a time machine s i said so.
How about a Portable AC i have one and it can do air and heat 59 - 82 or there's a window unit, oh yeah with the Portable do put it on its side it won't work
I have used a couple of cheap car window foil sun shields on a window and it helpedAlso you could get some shade cloth and put outside the window.
Put something over the glass on the outsidelouvers are best to keep off the sun but still allow light (you could use one of those cardboard things people put on their car windscreens)and get the air movingOne great trick is to have a water feature in front of a fan or by the door/window where the air comes inthe water will cool the air passing around itHeat rises, so think about putting in a ceiling vent or fan to draw the heat away.
I see many good answers here alreadyI just wanted to add that the reason a thick curtain doesn't keep the heat out is because the light is able to enter the room through the window and converts to heat on the curtains, staying in the roomIf you can reflect the light back out of the window then this will reduce heat, but as mentioned, this looks tacky To maintain your curb appeal, the use of shutters or a canopy over the window will be preferredOf course, a window unit A/C is not that pretty either, and if it's in a sunny spot, it won't be all that efficientYou will want to definitely get a canopy to shade the A/C unit so as to keep your energy cost downSo go ahead and invest in a canopy first and if you still need additional cooling then look into the other options.
a bridge that goes halfway into the river and comes back.for people who change their mind.
