Even though it might feel right to lower the setting on your thermostat on the hottest days, you should do RAISE the temperature inside your house.
Here's a look at what you should do:
There's some good give-and-take on this topic on my page - you can check it out HERE.
Here's why you should raise the temperature: Air conditioning units work harder and longer the lower you set them. If you set it too low, it could run non-stop. Some people even set it at their lowest setting thinking, "This will turn the cooling up to HIGH."
This puts lots of stress on the unit and uses lots of electricity - and it doesn't work.
Here's some great advice I found from a Heating and A/C company in Raleigh
There are two problems with putting the thermostat at such a low temperature. The first is that such a cold setting does nothing to make the air conditioning system work harder or faster at delivering cooling. All it does is make the AC’s compressor run longer until the thermostat senses the temperature goal has been reached. This wastes power and ends up with a house that’s too cold to be comfortable.
The second problem is that the larger the difference in temperature between the inside and outside of the house, the faster the house gains heat. When you set the thermostat temperature higher, you close the difference between the two and slow down heat entering the house. This makes it easier to maintain cooler indoor temperatures without requiring the almost constant running of the AC’s energy-draining compressor.
There's a bigger issue as well. The hottest days of the year are the days with the biggest electricity consumption of the year. If we all use a little less, it causes less strain on the power grid - which is good for all kinds of reasons!