What is the primary scientific reason why boiling water in open vessels takes significantly longer to cook food at high altitudes such as mountain peaks?

💡 Solution & Explanation

At high altitudes, atmospheric pressure is considerably lower than at sea level, which depresses the boiling point of water below one hundred degrees Celsius. Because water boils at a lower temperature, it cannot supply the higher thermal energy required to cook food efficiently in an open container, thereby increasing cooking time. Higher ambient temperatures do not occur at high altitudes, as mountain regions are generally colder. Atmospheric pressure decreases exponentially with increasing altitude according to the barometric formula.