1. Small battery power fan2. Foam cooler3. Knife4. Pen5. Later - batteries and ice1. Buy a small foam cooler - you can find it in liquor stores and they run about $3.2. Buy a small battery powered camp fan. Make sure it is smaller than the top of the cooler. I got mine at Target for $12.3. Lay the fan on top of the cooler. Draw around the fan with a pen.4. Carefully cut through the foam cooler. Depending on the size of the fan, you may need to cut a bit smaller than the fan. You want the fan to nestle down into the top of the cooler without falling down in. If you don't cut carefully you will break the lid.5. On the upper side of the cooler, cut some squares into the foam. Do this all around the cooler, but don't make them so close together that it weakens the cooler.Basically - you are now done. To make the air conditioner work, fill the cooler with ice and put the fan on top of the lid. Turn the fan on. The fan will draw warm air into the cooler through the holes in the side of the cooler and will blow cool out through the fan.Tip - put your ice into large ziplock bags. The ice will melt overnight and you can use the water in the ziplock for washing, drinking, and cooking the next day.Here's an alternative way of doing this. If you go this route, youneed to put the ice in a zip lock bag or water will run all over your tent. Do the same basic steps as shown above.If you have a small fan with a tilting base like this:Cut your holes on the bottom of the cooler instead of on the sides.The finished air conditioner will look like this:and will blow the air at a slight upwards slant instead of directly up like the first version. Just depends on how and where you are going to use it as to your preference.