Winter swimming area kept clear of ice by air bubbling near shore. Steps down from public sauna are kept warm for health enthusiasts who want to warm up before plunging into the cold. In early evening, saw visitors headed towards the building, then a woman emerged in near freezing temperatures to enter the water. We walked a path around the lake, illuminated after the sunset before 3:30 p.m. (Ahvenisto Lake, Hameenlinna, Finland) 20171202