I spent some time one recent afternoon (I know: Get a life!) taking my temperature with the ($50) home version of the new Exergen scanner, a little wand that you swipe across your forehead. I took my temperature four times this way and four times immediately afterward with a ($7.33) Medline oral thermometer from the drug store.
The two thermometers agreed on only two of the four trials, both saying my temperature was 98.2 Fahrenheit. On one other trial, the scanner registered 99, while the oral thermometer read 98.1; on the remaining trial, the scanner said 97.9, the oral thermometer, 98.1.
The scanner works by detecting heat in the temporal artery, which runs from the heart right below the skin in the forehead, but I gather it takes some practice to get consistent readings. You have to hold the button down while you are scanning the forehead and release it only when you are done, which takes a little getting used to.
According to Francesco Pompei, a scientist and engineer and CEO of the Watertown-based Exergen, which makes the scanners, the devices are now used in 30 percent of US hospitals. One advantage of the scanner, he noted, is that it is fast (a reading took 3 seconds, compared to 45 with the oral thermometer); another is that you don’t have to put it in your (or anyone else’s) mouth, rectum, or ear, a big plus for dealing with kids or elderly people.
In one study published last year in the American Journal of Critical Care, both oral and temporal artery thermometers were more accurate and precise than temperatures taken in the ear or under the armpit. The temporal artery method may also be quicker than rectal thermometers at detecting rapid changes in temperature, such as occurs when children with fevers are given fever-reducing drugs – though more research is needed.
As for me? I’m sticking with the oral thermometer. It’s cheaper, and I found the readings more consistent. If I had young kids and $50 to spare, I might switch to the scanner. But I’d be sure to take more than one reading – at least 30 seconds apart.