A critical mountain flying element is understanding your airplane engine’s ability to maintain safe working temperatures. Let’s face it, some airplanes have better designed engine cooling and vent systems than others. To illustrate the point I compare two airplanes I have owned and flown many hours. Cessna Cardinal versus Piper Archer II – both planes had an Lycoming 360 – On a hot day the cardinal would be redline oil temp 240F by 1500 agl, the Archer on the other hand would say in the middle of the green and rarely get above 200f even in a long climb to 10,500. The bottom line – just because the POH says your plane’s performance allows takeoff at 98 degrees from a 6500 ft field, delivering a climb of 500 fpm – that doesn’t mean it can sustain that performance and stay within safe temps. You may need to reduce AOA, increase the airspeed, and pull power (PS… reducing prop rpm usually does more for reducing heat than reducing throttle position). In any case that means having a plan B for your climb.