Drink lots of water. Sugar, caffeine, alcohol, and big heavy meals will make you feel warmer. Caffeine and alcohol will dehydrate you, so even if you drink a super big gulp soft drink twice a day, you still need 6 to 8 glasses of water. Large amounts of very cold drinks will fool your body into thinking you are cold, so your body's thermostat will try to warm you up. The idea that an ice cold soft drink is the perfect solution for your thirst on a hot summer day is something you have been brainwashed to believe by billions of dollars in advertising.
Water is better.
Learn how to read your meter. Your most recent electric bill has the last meter reading. If you subtract the new reading from last month's reading, you will know how many kilowatt hours you have used since the last bill. Be very realistic about what you will be able to pay for electricity, and then check your meter reading often. If you are unemployed, you may need to turn the air conditioning off during the day and go to an air conditioned library or other public space to meet your energy budget.