My daughter had a fever the day I got this thermometer, I have therefore tested right away. It is pretty (much like a telephone, dixit my daughter!), Convenient and fast but absolutely NOT RELIABLE! I tested it first on me, and I apparently had a fever every time - what a surprise! This put me a little in doubt. Then with my daughter 4 years, with each shot, the thermometer gave me a different temperature, sometimes varying by more than one degree! Yet I have followed all the recommendations. I had to repeat measurements with a rectal thermometer. How useful this thermometer so ?! Like another person said here "Security has no price."