Scuba divers during an ice diving class at the Sea Frogs scuba diving center in the Russian Far Eastern city of Vladivostok on January 30, 2022. The air temperature is –11°C (12.2°F), the water temperature is –2°C (28.4°F). Scuba divers undergo theoretical and practical training in ice diving and perform dives in the open water during the day and the night time as part of the Ice Diver NDL special program. (Photo by Yuri Smityuk/TASS)