I had an interesting vacation years ago that solidified my appreciation for indoor air conditioning. It was a week before my 18th birthday and my best friend John and I discovered this island just a few miles south of where we live that jettisons out into a large bay like a finger. There are these small huts on the island that you can rent by the night that basically just have bunk beds, a table in the middle for food and supplies, a few shelves, and a fire pit and charcoal BBQ a few feet away outside. The only way to get to the island and back is either by a ferry or a private boat. Somehow we managed to get John’s girlfriend’s dad to lend us a small boat for the weekend, since he was the manager of a local ocean marina. The ride over was beautiful and the island itself was gorgeous. I didn’t like how cramped in all of the huts felt during this holiday weekend with families and screaming kids right on our backs, but I was happy until I made the mistake of going shirtless without sunscreen for the first afternoon. That night–and every subsequent night from then on–was miserable. I had a sleeping bag and my sweaty skin kept sticking to it while the pain and itching from the burn raged on. There were no fans, no breeze, just deadly still, hot, humid evening air. I thought about my air conditioner and the times I’d come home with sun burns and crank the thermostat down and feel a cool breeze on my skin as my body tried to heal the damage. We take our HVAC systems for granted more than we take running water for granted. It’s hard to imagine a world without it until you’re literally in one.