Whether or not a camping fan will cool a tent depends on a number of factors. The first is the power of the camping fan itself—a more powerful unit will do more to keep you cool than a less powerful one. Placing something cold in front of the fan can also help lower the temperature (i.e., turning it into a swamp cooler). Next is the setup of the tent. If you have the rainfly on and all the doors closed, the heat of the day will be trapped inside your tent even as the nighttime temperatures cool. You also won’t get the benefit of air circulating naturally outside. Opening and securing the tent doors, along with vents your tent has, can help lower the temperature. Finally, whether or not a fan can cool a tent does in part depend on just how hot it is outside. Even the most powerful fan will only reduce your experience of the heat by 10 degrees or so. Check the nighttime lows before heading out on your trip to determine if you’ll be comfortable.