Because it is so dry in Joshua Tree, water is great for cooling off. According to my calculus-free, 200-level physics education, this works because a tiny bit of the heat energy stored in our bodies is used up every time a water molecule evaporates. It’s almost like the water molecule uses our body’s heat to achieve escape velocity, to become a gas. A lot of water evaporating creates a significant cooling. This is how sweating cools us, if we’re lucky enough to be in a dry area.

So when it is hot, which is every day in the summer, we get wet a lot. Inside, we have spray bottles handy so we can spray each other whenever someone starts complaining about the heat.

Above the stove is the handiest place for the spray bottle.

Outside, we often hose each other off. A good drenching keeps us cool even on the hottest days, until we are dry. Granted, that might only be for 15-20 minutes on a really hot day, but comfort is worth taking breaks that often.

If we’ve stored up some heat from a bike ride or forgetting to hose off, we also have a stock tank in the yard for dunking ourselves:

Reanna, cooling off.

The water stays cool even on the hottest days, also because of evaporation, so it is always refreshing to take a dunk. I built the little platform so when we drain the tank, we can water our plants.

12-inch dirt-filled stock-tank platform with screen lid and hose outlet. This photo was taken before I put plank decking on each side of the platform so we don’t get our feet dirty getting in and out.

We also got a “swamp cooler” from our friends Mike and Sarah. It wasn’t big enough to cool their house, but it’s good for our trailer. Reanna sewed a sleeve to funnel the air into our back window, so we didn’t have to cut a big hole in the wall.

Swamp cooler, on home-made platform

Reanna’s sleeve, held to swamper with a drawstring

Sleeve, inside window, held open by a wire frame

It makes a huge difference. A swamp cooler is simple and effective: A pump pulls hot, dry air from outside through wet sponges, creating cool, moist air inside. The physics involved is similar to sweat-cooling, except the heat energy used to turn the water into a gas is drawn from the air itself.

It requires simple enough plumbing that I could handle it myself:

A splitter where our (lead free) hose feeds the trailer, fitted with a compression joint to attach copper tubing. You can kind of see the copper-tube cutter (red) at the bottom of the frame.

Another compression joint, feeding the float valve that lets water in when the level gets low.

Swamper, inside: The float valve (blue) lets water in. The water pump (green) pulls it up and pours it down the three sponges in the left, right and back (removed) walls. The fan (drum at top) pulls the air in through the sponges and pushes it into the trailer. Simple!

The most fun way to use water to cool off, of course, is swimming. My mom got Reanna and me a month’s pass to the pool at the Joshua Tree Retreat Center (AKA Mentalphysics) as a wedding present, and we used that quite a bit. It was awesome. Thanks, Mom!

Reanna at the JT Retreat Center. Note luxuriously empty pool.

Reanna & Rob at the Joshua Tree Inn’s Hacienda Pines pool.

Matt at JT Inn pool.

Backstroke race at the Yucca Valley High School pool, also open to the public in the summer.

Kids in Ken & Katie’s blowup pool.