Say you have a PVC cage how would you use the heatpack's to heat the cage above 70 degrees?

Although in my area if the power goes out its normally an issue of getting to hot not to cold, but just in case.

What would you do for say its 90-95 degrees outside with the power out? I am just asking because we went 9 days after Hurricane Katrina without any power. We couldn't maintain the generator running because of lines at the gas stations and gas stations out of gas. It was hooked up to a few devices like our fridge and freezer and like 1 or 2 box fans but we couldn't run the central air.