This 2011 episode from prior hosts Sarah and Deblina covers polio, a threat in the early 20th century that often left victims paralyzed or dead. Vaccines caused an immediate drop in polio cases and today have nearly eradicated the disease.

Behind the Scenes Minis: Pollution Olympics
24:24

Notable Early Women Olympians
40:11

John Evelyn's 'Fumifugium'
39:35