If you’re inside, it’s best to open two windows, whether you’re in a car or a building, to get a breeze flowing. If you have only one window open, fresh air entering is going to collide with hot air exiting, and your room isn’t going to get much cooler. It’s like people at movie theaters, where there are six doors but everyone is trying to simultaneously enter and exit through the same one. If you open two windows, the cooler outdoor air can enter more easily because the hot indoor air will be mostly exiting through the other window.

You can also place a fan near one of the open windows, facing outward so it’s blowing hot air out of your room. If you don’t have a good fan, we like this mountable, high-velocity Lasko floor fan ($65) and this Vornado floor fan ($65). Many home air purifiers also have adjustable fan settings that’ll blow purified air on you, as well.

You can try blackout curtains ($36) or thermal curtains. Yeah, it’ll be dark inside like a cave, but it’ll also be cooler. Even regular curtains, which will allow more light in, will reduce some heat as long as they’re room-darkening and not sheer.

You can also buy an evaporative cooler, such as this NewAir 300 square-foot model. Evaporative coolers work by passing air over a water-soaked pad, which humidifies the air and lowers the room temperature. There are caveats, though. They work well only in dry environments. Even indoors, you generally have to live where the humidity is low to get the most out of these machines, although you can use them outdoors wherever, when the humidity isn’t too high.

If you can handle the heat during the day but must have a cool bed at night, the BedJet 3 ($ 399) is a favorite of ours. It’s pricey, though. If you’re spending hundreds of dollars, you may just want to give in and buy a window AC unit and find a closet for it the rest of the year.

To Cool Your Body Down, Try These

Photograph: REI

You’ve got four major arteries on your body where application of something cold or hot makes a great impact on your body temperature: your groin, armpits, and the back of your neck. The easiest one to chill is the back of your neck. Cool water is your friend, here, but even ambient-temperature water is better than nothing. When I was a kid, mowing the grass outdoors in North Carolina’s brutal Piedmont summers, I used a Kafka’s Kool Tie ($11) that I borrowed from my father. Kool Ties are full of polymer crystals that absorb a lot of water, so one dip in a sink or under a hose spigot lasts for many hours. It works, although when it’s really waterlogged it becomes quite heavy. It also bulks up and can reduce your head movement.