Alex Foster spent the winter months of 2019-2020 learning about winter swimming and cold water immersion at the Serpentine Swimming Club, in Hyde Park, London. This is podcast is about his immersion in the club and its waters, and his MPhil thesis in Medical Anthropology on this topic. The thesis is available at www.lxvswim.org. Additional music is James Blake's cover of Don McLean's 'Vincent', and Glenn Gould's 1981 recording of Bach's Goldberg Variations.