Air-conditioning units and central heating/cooling systems are a luxury that will keep you cool…and broke. If you can’t afford to run the A/C all day and night, think about reverting to fans. Not those cumbersome old spinners from your youth, but the modern alternatives that do more than just move dusty air around the room.
If you have ceiling fans with speed settings, adjust it to rotate counter-clockwise at high speed as this creates a wind chill breeze effect. Another handy hack is to turn on your bathroom exhaust fan and leave it on as this will expel hot air out of the room.