Indoor tents are all the rage in South Korea this winter. Apparently they keep you really warm and save electricity as well. In fact, some tent-users say their heating bill has been reduced by half. While the temperature in rooms gets as low as 19 degrees Celsius, the 40,000 won (US$37) tents are quite cozy at 23 degrees.

Given their multiple benefits, these tents are flying off shelves in South Korea. One tent maker claims to have sold 4 million in just a couple of weeks. Thousands of tents are on back order, and manufacturers are rushing to make more. We don’t know who came up with the ingenious idea, but it looks like almost everyone has caught on.

This winter has been pretty harsh for the South Koreans; they are facing power blackouts and surging energy costs with six of 23 nuclear reactors being shut down. People have been looking for cheaper heating methods that save electricity, and the tent is apparently working wonders for them. Families are sleeping in tents setup within their homes to keep themselves warm. Some of them have placed tents on top of beds for extra warmth.

The Lees, who live in an apartment just outside of Seoul, are one such family. They have a tent in their living room that’s specially designed for indoor use. The family-of-four huddles inside it while watching TV or just to sit around and keep warm. Despite their best efforts to keep the cold out, their living room is 18 degrees, while inside the tent it’s a nice and warm 26 degrees. The children no longer sleep in beds; they prefer the tent at night as well. The Lees got the tent idea from a neighbor.

The average temperature during the day is around minus 10 degrees Celsius, but families like the Lees aren’t worried about their kids catching colds, thanks to their toasty tents.

Sources: RocketNews24, Business Insider