So many great suggestions--if we lived somewhere it gets down to a reasonable temperature at night, LOL! Even our night temps are just fine for the reptiles.
The way our house is designed, there are few good locations for the aquarium, and there are reptiles in every room. Yeah, I'm a crazy snake and lizard lady!
So, the current house temps--85 F--are fine for all the reptiles; hence, we've turned off all their lights and heat to reduce the amount of heat inside the house. Moving the reptiles near the aquarium would take at least a week; they are in large natural habitats that would have to be broken down, taken downstairs, and rebuilt. Not an easy task due to their size. And with all their lights and heat off and nighttime temps as high as they are, moving the reptiles wouldn't be any additional help.
We have the pedestal fan set up to blow across the aquarium, and the water temps in the aquarium are staying at 81 degrees.
Last night, we were able to open the windows and increase air cooling starting at about 2 a.m. (that's when the outside temps finally dropped down to the house temps). We had to close all windows again by 9 a.m. when the outside temp hit 82 F. Fortunately (!!!), the heat wave anticipated today is delayed yet again, and the National Weather Service and Mesonet dropped the predicted high from 102 to 95!! YAY! Now they are not predicting any triple digit temps for the rest of the week, which is quite a relief!
The gouramis seem to be doing fine. The shrimp are hiding (I hope); my husband saw two of them early this morning, though, so they survived the first day!
The technician is supposed to be returning very soon to work on the system again. We have a geothermal system, so many AC techs can't work on it. We are definitely looking forward to seeing him!
I am reminding myself that patience is a virtue . . .