Even in very hot climates, below ground soil temperatures can be cooler than an air-conditioned house or garage. When you have a house on a slab, and dug root cellars are impossible because of high water table levels, you can still “build up” by putting in an earth berm and storing preps under it.
If you have enough land, you can make the berm part of decorative landscaping, or use it to increase privacy and reduce noise from the road. Even on smaller plots, you may be able to use an earth temperature moderating technique that is more common in the north: waterproofing the base of the house and building up an earthen bank on the north side of the house. In the north, this is done to reduce heat loss in winter and increase coolness in summer. ( In the south, it may still make the house a bit cooler and can be done on all sides.)
The berm can be left sloped or end in a vertical wall using railroad ties, concrete block, or other methods. In any case, you can then bury your preps under a couple feet of cooling soil. Even OPSEC is not too much of a problem if you are seen busily gardening and planting flowers (in pots, so they can be removed easily) over your preps. If anyone asks why you are building a berm around your house, the answer is “earth cooling to save air conditioning costs”, which is also quite true. You are Green! You may even encourage your neighbors to “go green” too. That way no one will notice that your house is different.
Sandy soil will make for better drainage and easier digging up of preps when needed. Why are you buying so many bags of sand? To improve soil quality, of course, so there are more flowers. Or if you wish, grow veggies.
Earth berming isn’t as handy as a root cellar or basement, but it’s much better than having all your food spoil after a week-long power outage when the air conditioning fails and the generator runs out of fuel.
JW from New York