Lascaux paintings: © JoJan, CC BY-SA 4.0; Messner and Kammerlander with Ötzi: P. Hanny © Tappeiner I-39011; Avercamp’s Winter Landscape with Skaters: © Rijksmuseum Amsterdam, CCо 1.0; Frost fair: © Bridgeman images; Death of Willem Barents: © National Maritime Museum, Greenwich, London; Micrographia: © Wellcome Collection, CC BY 4.0; Felbrigg Hall: courtesy of the author; Yakhchal: Konstantin Novakovic/Getty Images; Ice-harvesting: © Library of Congress Prints and Photographs Division; Mer de Glace postcards courtesy of the author; Elizabeth Le Blond: © Alpine Club Photo Library, London; Mammoth postcard: courtesy of the author; Engraved tusks: Delporte, with permission from Don Hitchcock; Wilhelm Braune’s sectioning: © NLM; Naked soldiers: © Sächsische Landesbibliothek – Staats und Universitätsbibliothek Dresden (SLUB); Guerra blanca: © Museo Fedaia della Grande Guerra; Langmuir, Vonnegut and Schaefer marvel at the ‘cold box’: Schenectady Museum; Hall of Electrical History Foundation/ CORBIS/ Corbis via Getty Images; Cannon on the Cima Ghiacciata: Tom Isitt; Iceberg-towing: Donald Iain Smith/Getty Images.