As long as your air conditioning system is properly sized for your home and you maintain it well, it should be able to help you get through excessively hot conditions in your area. However, it's a given that the more you use the air conditioner, the more stress and wear are placed on the system and its parts. If your city is experiencing an excessive heat wave, take a few extra steps for air conditioning maintenance so that you continue to stay cool, and the system doesn't fail prematurely.
Help It Along
While your air conditioner was literally built to keep you cool in hot weather, it works a lot better if you help it along. Reduce the heat that gets into the house so that the system doesn't have to deal with as much heat; this includes blocking drafts under exterior doors, reducing heat generation in the kitchen (in other words, use the microwave, not the oven), and keep the blinds closed and the slats turned to block light from entering rooms. If you haven't changed filters in a while, now's the time. And if you can, shade the exterior compressor unit for central systems. While that last tactic is accepted as a way to increase unit efficiency but is not quite proven to work, it certainly can't hurt.
Don't Turn It Off
If you leave your house during the day, don't turn off your air conditioner. Keep it on but with the thermostat at a much higher temperature. Not only will that prevent your home from becoming too hot during the day, making you very uncomfortable when you get home, but it also helps prevent the air conditioning from experiencing a lot of stress when you turn it back on. When you have it on, but at a higher temperature, the unit will have to deal with cooling air that is somewhat hot, to a point. But if you turn it off, when you start it back up again it will have to cool even hotter air that has been building up all day, that increases the wear on the unit.
Schedule Extra Maintenance and Inspections
If you've been through a typical heat wave in your area, your air conditioning should be fine. If you've been through an excessive heat wave, however, where conditions were unusually bad or had a complicating factor (such as wildfire smoke, the ash from which can get into your home and clog filters, or excessive humidity), a call to the air conditioning company could be a good idea when the heat wave is over. Give the system some extra maintenance so that any effects from the stress of the heat wave are fixed.
Keep up with the maintenance schedule for your air conditioner so that it is ready to handle hotter weather. The easier you can make things for the air conditioning system, the easier it will make life for you during the summer.