CLINICIANS have been under the impression that the skin of patients with congestive heart failure, especially the skin of the extremities, seemed cooler than normal even at a time when fever was present. Steele and Cohn1 have made objective measurements relating to the temperature of the skin of certain areas of the body and to the rectal temperature in patients with heart failure in an attempt to arrive at an understanding of the fever which occurs in heart failure unrelated to any infection. They found that the "temperature of the surface in cardiac patients is lower than in normal individuals, while that of patients with infectious fever is as high as or higher than normal. The difference in behavior leads to the conclusion that the elevation of rectal temperature in heart failure depends on processes incidental to heart failure itself."1a Certain things are known about the circulation in