Heatwave is the thirty-seventh episode of the first season in The Mr. Men Show. This episode centers around a the Mr. Men and Little Misses surviving from a heatwave.
Little Miss Calamity's ceiling fan blows her away; Mr. Per(s)nickety's trip to the beach results in a major row; and Mr. Rude's air conditioner brings unwelcome guests.
- Miss Calamity's Plot: Miss Calamity's fan breaks off the ceiling and develops a killing mind of its own! Miss Calamity tries to get away from it. She calls the Dillydale Ceiling Fan Company, but it is no use. It soon sends her house off the cliff, even breaking her gnome.
- Mr. Persnickety and Mr. Messy's Plot: Mr. Persnickety's radiator breaks down on the way to the beach and he is with Mr. Messy who makes a big mess.
- Mr. Nervous' Plot (US version only): Mr. Nervous imagines he's on Mercury, the planet close to the Sun. He meets a space robot which starts shooting lasers at him. It's shown he's in Miss Scary's garden with the sprayer spraying on him. (Not in the UK)
- Mr. Rude's Plot: Everyone knows that Mr. Rude is the only Mr. Man in Dillydale who has an air conditioner (it was unknown who started the rumor, but Little Miss Chatterbox was the one who started the chain of telling people) and everyone barges into his house.
- Mr. Nervous' plot is absent in the UK version but was viewable on a DVD.
- The show that Mr. Small watches in Mr. Rude's plot is an actual episode from Fair.
- This is the second time The Mr. Men Show is watched in-universe, the first being Inventions.
- The ending of the episode doesn't audicate properly in the UK version.