The Korean Peninsula was battered by a wave of freezing weather this winter. But while most South Koreans kept toasty in modern apartments and office buildings, many North Koreans are forced to rely on poor heating methods in a potentially deadly struggle against the cold.

North Korea’s central radio broadcaster issued extreme cold weather warnings for the entire country in late January. Pyongyang reportedly dropped to -2 F (-19 C), while the northern regions were forecast to plunge to below -20 degrees F (-30 C).