When there’s a heat wave in the Wizarding World, many witches and wizards enchant their robes to keep themselves cool in the record breaking temperatures. Many young muggleborns question how all the wizards can stay cool in long black clothing until someone finally explains the charm.
Mr. and Mrs. Dursley, of number four, Privet Drive, were proud to say that they were perfectly normal, thank you very much. They were the last people you’d expect to be involved in anything strange or mysterious, because they just didn’t hold with such nonsense.
Harry Potter and the Philosopher’s Stone, 26th June 1997.