In Iceland and other Nordic countries, it’s not unusual to leave your infant to sleep outside even in freezing temperatures. Of course, they are dressed appropriately and covered up, but even then, most parents from other countries would feel wary about leaving their infant in cold weather. However, in Iceland, it is believed that sleeping in the cold boosts children’s immune system and contributes to a better rest. Maybe there is truth to that, because the average life expectancy in Iceland is 82 years, which is 10 years more than the world’s average.