Whooping cough

Whooping cough was an Earth disease. Before the late 20th century it was often fatal.

The First Doctor convinced young Craig Atkins to pretend he had whooping cough. This was so Prentice would turn off the temporal technology he was using to keep Keelmouth frozen in 1933, and reintegrate the town into the actual time period of 1999. (PROSE: Bide-a-Wee)