It's the scary image that's become an iconic symbol of the worldwide coronavirus crisis: medical personnel pointing a digital thermometer at foreheads, testing for any sign of a fever. From airports to cruise terminals, we've seen these health screenings all across the globe. But what if those thermometer readings aren't accurate? The devices being used are meant for pipes, plumbing and other industrial uses. Experts say when used on humans they can be off by as much as 7 degrees. Instead, medical personnel should be using medical grade thermometers which touch human skin, and need to be sterilized between uses, according to experts.