Why buy this?
You ought to take your body temperature daily during an infection by the viruses that cause a common cold.  Common colds usually do not enhance body temperature, but bacterial infections do.  If you have a sustained high body temperature, you should immediately consult a physician and that doctor can then get you an antibiotic that will most often cure infections that if unchecked can develop into a disease that can be fatal (e.g., diseases of the lungs).
This is a relatively new way of measuring body temperature.  The device picks up body temperature by applying it to the forehead.