BOILING AT ALTITUDE
Because the boiling point of water decreases with lower air pressure, when used at high altitudes a standard kettle will never trigger the thermostat to automatically turn off. Water boils at 100 degrees Celsius at sea level; at 150 metres above sea level, its boiling point is lowered by about 0.5 degrees Celsius, continuing to reduce as altitude increases. If you want to make a cup of tea when high in the mountains, a variable temperature kettle is a good solution. This enables the user to alter the temperature setting depending on their elevation, allowing the kettle to automatically trip when the water boils.