When you are having a major heat wave, if you want to try to keep the central air conditioning working great in your home the best thing to do is to keep all of your blinds closed! If you have curtains, the same thing applies.
Yes it makes your home dark and dreary looking, but it really helps the central air conditioning do its thing and keep your house cool.
Especially if you have an older central heating and air conditioning system you will want to do this. Older central heating and air conditioning systems do not have the same power as the more modern and up to date central heat and a/c units do. If you happen to have a brand new and up to date central heating and cooling system, you may still want to keep the blinds or curtains closed, but it is not as essential as it is if you have an old HVAC system. I have learned this over the years through trying different things when it got really hot out. My central heating and air conditioning system is an older model so it sometimes can not combat the bad heat of over one hundred degrees when it happens. But when I close everything, it seems to work pretty well. This is my tip to you on how to keep your home nice and cool through the worst of a heat wave. Even ones over one hundred degrees! Living in the southwest is how it is most of the time here. So this is always a must for me and my lifestyle to be totally honest with you.