Well, you must mean "What can you do to be better prepared when it happens again?"

'Cause even I cannot prevent a thunderstorm with 90 mph winds, falling 100 year old sycamore trees, and power outages, much less heat waves.
1. I will not have a tank upstairs. My basement stays cool no matter what, so that's where all tanks will go from now on. If we have a power outage in winter, I will need a generator to heat the water. Now in summer, once everything was downstairs, I kept it all alive with battery operated air pumps. But it was on the edge of being too cool. Water got to 74 F degrees. We have not lost power in winter for 15 years.
2. I should get a battery operated pump as Edgar advised.
3. I need a larger watt power inverter and possibly a marine battery. I would also like to get a solar powered recharger. It would have come in handy.
What saved me:
1. Bubble boxes--the kind that fishermen use to keep minnows alive in the bucket.
Very cheap and essential. Get the ones that take 2 D cells. They worked for a couple of days straight. Also the B11 silent air ones that come on automatically when the power goes off. Buy enough of these to cover the essential tanks at your home. Then buy 4 or 5 bubble boxes. You will use them. Also have on hand lots of extra airline tubing and valves, and D batteries.
2. Quart ziplock freezer bags. Putting on gloves when your hands are wet or sweaty is impossible. The bags protected my hands from bristle worms when I was moving all that rock in 100 degree non-airconditioned weather.
3. Hot water in 64 oz bottles, sealed. I set one in each tank to warm the water.
4. Minijet 606 and non kink tubing. Used it with my dinky power inverter to keep the bioball wet/dry ....wet. Also had it going to each tank in my system by turns so the water would drain to my sump thru the filter. Got a little water exchange there.
The minijet uses like 5 watts, so it ran for hours on the inverter and jump-start battery.
5. Extra 18 gallon tubs. Used them to transfer rocks, corals and water, partially filled. Husband used them to transfer the contents of our refrigerator and freezers to the dumpster, so nothing would leak on his van. Becomes a tank in a pinch. Also good for mixing water.
Things that did not work as expected:
Battery operated T5 lights. 12 inches. Consumed batteries after a couple of hours. Unreliable.
Cheers,
Kathy