To the Editor:—
The Question and Answer, "Athletics and Climatic Stress" (JAMA188:616 [May 11] 1964), prompts me to theorize on the genesis of myocardial infarction in cold weather and to submit the following observations:
In short, heavy physical exertion
Persons who ski or skate in subfreezing temperatures seldom wear heavy clothing and seldom experience any particular discomfort from the cold and wind.
Persons who suffer heart attacks while shovelling snow are generally middle-aged men heavily wrapped in several layers of warm clothing.
While shovelling snow myself, for periods up to an hour in temperatures between 5 and 20 F, I experience no sensation of cold, either superficially as goosepimples, or deeply as chills, though wearing only a short-sleeved, unbuttoned shirt and trousers and bedroom slippers. When I wore hat, gloves, overcoat, and galoshes, I became overheated, perspired profusely, and had to take more frequent rests.