"Cool Air" is a short story by the American horror fiction writer H. P. Lovecraft, written in March 1926 and published in the March 1928 issue of Tales of Magic and Mystery.
The narrator offers a story to explain why a "draught of cool air" is the most detestable thing to him. His tale begins in the spring of 1923, when he was looking for housing in New York City. He finally settles in a converted brownstone on West Fourteenth Street. Investigating a chemical leak from the floor above, he discovers that the inhabitant directly overhead is a strange, old, and reclusive physician. One day the narrator suffers a heart attack, and remembering that a doctor lives overhead, he climbs the stairs and meets Dr. Muñoz for the first time.
The doctor demonstrates supreme medical skill, and saves the narrator with a combination of medications. The fascinated narrator returns regularly to sit and learn from the doctor. As their talks continue, it becomes increasingly evident that the doctor has an obsession with defying death through all available means.
The doctor's room is kept at approximately 56 degrees Fahrenheit (13 degrees Celsius) using an ammonia-based refrigeration system; the pumps are driven by a gasoline engine. As time goes on, the doctor's health declines and his behaviour becomes increasingly eccentric. The cooling system is continuously upgraded, to the point where some areas of his rooms are sub-freezing, until one night when the pump breaks down.
Without explanation, the panic-stricken doctor frantically implores his friend to help him keep his body cool. Unable to repair the machine until morning, they resort to having the doctor stay in a tub full of ice. The narrator spends his time replenishing the ice, but soon is forced to employ someone else to do it. When he finally locates competent mechanics to repair the pump, it is too late.
He arrives at the apartment in time to see the rapidly decomposing remains of the doctor, and a rushed, "hideously smeared" letter. The narrator reads it; to his horror, he learns that Dr. Muñoz died 18 years previously. Refusing to surrender to death, he maintained the semblance of life past the point of death using various methods, depending upon refrigeration to retard decomposition.