Wet Bulb, Globe Temperature Hand-held Heat Stress Monitor- Determines true heat stress temperature by accounting for air currents, relative humidity and solar load in addition to air temperature and relative humidity. Designed to monitor environmental thermal conditions, this instrument is an industry breakthrough for outdoor sports.The unit has four measurement parameters which include WBGT (Wet Bulb Globe Temperature), TG (Globe Temperature),TA (Air Temperature) and % (Relative Humidity). With a temperature accuracy of +-2F (+-1C) and an RH% range of 0 to 100% RH this instrument will be invaluable to coaches, team trainers, athletic directors and sports medicine practitioners.