You can buy a temperature gun and measure the temps yourself. Go to Walmart or other place that sells them. You should measure the most important part of the drone, the heatsink at the bottom. Look for the hottest spot, and that is your max temperature that you should go by. The internal cooling fan kicks on when the core board temp get to be 110° - 116°, and it will keep the drone cool enough to avoid overheating. If you are flying when the temperature outside is over 100°, keep your temp gun close, and measure before and after the flights. Heat sink temperature should never get above 125° or you risk frying your FC ESC board.