THE SFA/MASS RATIO The SFA/Mass ratio is a term used to describe the percent-age  of  skin surface  area  (SFA) to  body  mass.A higher SFA/Mass ratio has been linked to in-creased sweating and a lower risk of heat-related illnesses, such as heat exhaustion and heatst roke.This is particularly relevant for athletes and individuals who engage in physical activity in hot en-vironments, as they may  be  at  increased  risk  of  heat-re-lated illnessesFor example, females typ-ically have a higher SFA/Mass ratio than males.The  SFA/Mass  ratio  varies among  humans based  on age, sex, and body composition.