Changes Produced in the Distribution of the Blood Supply of the Skin and the Upper Respiratory Tract by the Application of Localized Drafts of Air *

The temperature of the human skin is the resultant of two influences;--the heat brought to the skin by the blood stream and the heat loss from the skin surface. Any alteration in either one of these factors serves to produce a change in skin temperature. Therefore, under given environmental conditions, the skin temperature at a particular time and place is a measure of the change in the amount of heat brought to that point by the blood stream through an increased flow of blood, by an increased temperature of the blood, or by both. If this reasoning is correct, it may be seen that by properly controlled measurements of the skin temperatures we have a means of evaluating the character of the blood flow to the peripheral areas of the body. And, further, it may be seen that if the body as a whole is maintained at a fixect temperature, and if one isolated extremity is subjected to additional heat loss, such, for example, as that produced by a draft of cold air, the resulting changes in skin temperature may be taken as representing the change in blood distribution brought about by exposure of the isolated portion of the body to the particular draft used in the experiment. The experiments herein described have been conducted in an effort to determine some of the effects of such localized drafts on skin and body thermal changes.