I live in the high desert of southern Utah and here is what I found really helps in the hot days of summer (absent humidity of course). I have 2 trees in the yard where I placed a pop-up sprinkler head on top of a 20 foot section of pipe and when I need the area cooled off I connect a hose and let the sprinkler rain down on the area, including the trees, and the water cools the air and the trees and the ground and makes the area comfortable for working or sitting. One of those trees is in the chicken run so I can cool off their area on the really hot days, and the moisture to the ground helps compost the wood chips and chicken manure and then the wet ground attracts insects for the chickens to eat. If you don't want to run the pipe and sprinkler head up the tree you can use a hose to spray the trees and bushes and surrounding area with cool water. (PS: last year when a wildfire was approaching the neighborhood I turned on both sprinklers to soak the area and used a hose to wet everywhere around the house)
The house has central air conditioning but I have a swamp cooler (evaporative cooler) in the garage. It is a window unit I used before I had the air conditioning installed in the house so I have it on a garden type wagon so I can roll it around where ever I need a cool breeze. In the mornings I turn on the swamp cooler in the garage to cool off the garage and I have a fan blow the cool air from the garage into the house. I do not open a door or window, I just let the cool, moist air fill the area because it's a desert and relative humidity is rarely above 20% during the summer so the added moisture is a good thing. In the morning I will open the door to the house and use a fan to blow the cool air into the house, keeping the garage and the house cool. I can usually leave this running until mid afternoon, and sometimes all day, depending on the day, and it cuts down on the run time of the A/C unit. Again, the added moisture in the house is a good thing in the desert.
Speaking of swamp cooler, if you need a little extra cooling add ice into the water in the swamp cooler, or buy a few gallon jugs of water and freeze them and then place a gallon jug of water into the swamp cooler to chill the water a few more degrees. When the water in the jug melts place it back in the freezer and replace it with another frozen water jug.
Wet your shirt, or on really hot days wet all your clothes. If there is a breeze it will feel rather chilly, of there is no breeze or if you are inside aim a fan in your direction and it will keep you cool. You can even use a fan outside if you are working in one area and need air movement.
Drink plenty of water, or better yet ice water. The ice water will cool you off on the way in and the more water you can pass the more heat you will pass out of your body. After about 20 some years of working in Vegas I had worked my way up to over 3 gallons of water a day. That is a lot but some very hot days I might have only relieved myself 3 times a day because so much water was lost through sweat/evaporation. Even if taking vitamins everyday you should take in enough water to have at least one clear urine sample during the day. If the urine isn't clear at least once a day you are not flushing enough water through your system.
Use ice packs on your body during the day, and maybe at bedtime. While I was working patrol in the desert I would have a small cooler in my patrol car with a dozen or so 3x5 soft gel ice packs. The second half of my day shift I would rotate the ice packs to keep myself cool. With the vest (which was equivalent to about 100 glad trash bags wrapped around my body) I would place one or two ice packs inside my vest over my breast bone to help keep my body cool, and after long periods of time out in the heat I would place an extra ice pack behind my neck and add another icepack under my butt while sitting in the care. These small ice packs will stay frozen at least 45 minutes, and still be cool for up to an hour. I know most of you are not wearing a bullet proof vest at home but you can stick them in your pockets or tuck them in your shirt or bra. the "shocking" chill only lasts a few minutes, just make sure there is at least on layer of T-shirt material between the ice pack and your skin. I never had an issue with frostbite doing this in the heat of the day.
We all know a hot dinner is delicious, but cooking a meal inside the house is just making the house hotter and there are plenty of meals you may enjoy as "leftovers" when they are cold. Consider BBQing a bunch of chicken and eating it cold out of the fridge as a "left over". By BBQing the heat from cooking is outside and you are not heating the inside of your home. I love a good cold chicken leg or chicken thigh and you can still add your favorite BBQ sauce or ketchup or whatever even when it is cold. Cold meals are still yummy and the cold food cools down your body. Along with the cold meat you can have a cold salad and some cold tea or lemonade or cold water.
Finally, get a pool. It doesn't have to be a real pool, I initially had one of the 10" Intex inflatable pools in the yard just to sit in after a long day building my house or working in the yard. It was only about 24"deep but as long as the water is below 98* it will cool your body and odds are with the cool night temperatures even in the heat of the summer the water will stay about 80* or so. I never added chlorine or chemicals, ever couple days or so I would drain out about 1/3 of the water towards the nearest tree or bush and refill it with fresh water. Since I was just sitting in the water to cool off I was not worried about getting "bad" water in my mouth or nose or eyes. After an 8 hour day of building my hour house I would sit in the pool to cool off before going to my part time job in the evening, the I would sit in the pool after woork at night to cool off before my shower before going to bed. There is no better way to cool off than sitting in a cool pool/bath.
