Cold-Plunging With Maine’s ‘Ice Mermaids’

When I met Ida Lennestål for a plunge on a cold January day, she was pulling an ax from her car and switching into warmer boots. A few minutes later, she lit a fire in a nearby sauna — a small building cobbled together from a former fish house and an old stove — before we walked the short slope down to a frozen pond near her home in Georgetown, Maine.