Efeect of temperature on hospital admissions for myocardial infarction in a subarctic area

In a study of the effect of mean daily temperature on the admission and fatality rates of 771 patients with myocardial infarction the admission rate was found to be significantly higher on cold (temperature below 0 degrees C.) than on warm (temperature above 0 degrees C.) days. The fatality rate was almost equal in cold and warm weather. Thus the seasonal fluctuation in the admission rate of patients with myocardial infarction is probably due to a direct effect of environmental temperature.