CHICAGO (AP) - When it comes to taking babies' temperatures, bottoms beat ears and foreheads, a Harvard Medical School study suggests.

The study compared a new infrared forehead thermometer with an ear thermometer and the tried-and-true rectal method.

The forehead device missed 40 percent of fevers detected rectally but was more accurate than the ear thermometer, especially in detecting high fevers.

The ear thermometer, widely used in hospitals and favored by many parents because it is easy to use, missed about half of low-grade fevers and 24 percent of fevers above 39 degrees Celsius (102.2 degrees Fahrenheit), Drs. David S. Greenes and Gary R. Fleisher reported. The forehead device missed just 6 percent of high fevers.

The study, published in the March issue of Archives of Pediatrics & Adolescent Medicine, was funded by Exergen Corp., which makes the forehead thermometer studied. The device, about the size of a cellular phone, measures body temperature at the temporal artery when stroked across the forehead.

Rectal thermometers have long been considered the gold standard for accurate temperature-taking in infants, though they can cause discomfort and, less commonly, rectal injury. Some doctors do not recommend ear thermometers for infants because their small ear canals can make getting an accurate reading difficult.

The study did not include oral thermometers, which are not advised for infants or very young children, who have difficulty keeping the devices under their tongues and risk biting or breaking them.

Greenes noted that low-grade fevers could in some cases be a sign of serious illness in infants, such as meningitis and pneumonia.

A consumer model of the forehead thermometer called Sensor Touch, similar to the one studied, was sold briefly in stores last year and will be re-marketed in a few months under the name Temporal Scanner, costing about dlrs 80. That compares with about dlrs 50 for ear thermometers and under dlrs 10 for most rectal thermometers.

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