The conclusions of research vary depending upon the amount and duration of pressure that is simultaneously applied with varying temperatures (Patel, 1999; Kokate, 1995). However, higher ambient temperatures have been shown to cause an increase in tissue metabolism and oxygen consumption on the order of 10% for every one degree Celsius (Brown, 1965). Thus, the oxygen requirements of high risk patients who already possess compromised tissue may be increased. Any increase in temperature in combination with pressure is believed to increase the susceptibility of the tissue to injury either from ischemia or reperfusion when pressure is relieved . The application of repetitive surface loading alone also induces an elevated skin temperature of 5 degrees C or greater (Vistnes, 1980). In addition, peak skin temperatures have been found to be proportional to the magnitude and duration of the applied pressure .