Although there is some controversial speculation, Hugh Laurie was not sick during filming. House was supposed to have a cold in the first two-thirds of the episode, and Laurie incorporated the vocal symptoms into his American accent.
Dr. House looks into buying a motorcycle. Hugh Laurie is an avid motorcyclist.
21° Celsius converts to 69.8° Fahrenheit; average body temperature is 98.6° F or 37° C.