(My friend worked as a lifeguard in a swimming pool).
Customer: “This pool is too cold, can’t you see my baby is going blue?!”
Lifeguard: “I’ll check the temperature for you, but as all the other babies are fine it shouldn’t be too cold.”
(He takes a temperature reading and it is nearly 35 degrees C/95 degrees F.)
Customer: “Well, it’s still too cold.”
Lifeguard: *gives up* “Very well, if you would like to boil a lobster that’s fine by me.”
(Unfortunately, the customer had no sense of humor and shortly thereafter my lifeguard friend had no job.)