Tips for keeping shrimp tank cool?

I have a 2.5 gallon and a tiny heater that keeps it at abt 78 degrees. I know ideal breading temperature is abt 73 degrees (i have a few cherry shrimp. A couple females & one male) but i live in texas and when i take the heater out, it is naturally sitting at like 76 degrees. Is there any tips or items that i could use to cool down a tank this small…?