Question

why is it advisable to use pressure cooker at higher altitudes

Answer 1

Because it contains black color and black is the good absorber of heat

Answer 2

"At higher altitude atmospheric pressure is lower than near the sea.This cause the water to boil at a lower temperature (below100),due to this it takes lower time for to be cooked.A pressure prevents boiling of water at lower temperature and leads to quicker of the food."