In aviation, hot and high is a condition of low air density due to high ambient temperature and high airport elevation. Air density decreases with increasing temperature and altitude. The reduced density reduces the performance of the aircraft's engine. Aviators gauge air density by calculating the density altitude.
"Hot" and "high" do not have to be mutually inclusive of one another, though this tends to be the exception. If an airport is especially hot or high, the other condition need not be present. Temperature and pressure altitude can change from one hour to the next. The fact that temperature decreases as altitude increases mitigates the "hot and high" effect to a small extent.
i personally struggle to get concorde off the ground with the afterburners going full bore same with katmandu in nepal simply wont take off ?