On winter mornings in Harbin, where the air outside could freeze your eyelashes, I would wake up on a bed of warm earth.
Harbin, where I grew up, is in northeast China. Winter temperatures regularly dip to -30°C and in January even the warmest days rarely go above -10°C. With about 6 million residents today, Harbin is easily the largest city in the world to experience such consistent cold.
Keeping warm in such temperatures is something I’ve thought about all my life. Long before electric air conditioning and district heating, people in the region survived harsh winters using methods entirely different from the radiators and gas boilers that dominate European homes today.
