Right out of the package, we loaded it up with the encluded batteries and started trying it out. It is a great guide for checking on a little one who seems to be feeling off. Without having to try and get a thermometer under their tounge or armpit when they already don't feel good, you just point it at their forehead or neck and can tell if they have an elevated temperature. We compared it with a regular thermometer and they were very comperable. This is a great tool to add to your medicine cabinet.