In 95% of population there is a relation between the temperature of forehead and temperature of body.This is the reason why we touch the forehead to know if a person has fever or not.<br /><br />Thermo Test Temperature Revealer is a fast and sure way to get changes of temperature, and more especailly when using and carrying a classical thermometer is not practical. You just have to put the strip on the forehead during 15 seconds to know the body's temperature. It is very practical for children, because they don't need to be undressed and moved.