(Chicago Tribune) -- Oh, to be born in 2012.

Used to be a fever meant your already unhappy, uncomfortable infant was subjected to a rectal temperature check. Now pharmacy shelves are lined with gadgets that promise an accurate reading with the mere swipe of a wand. A new thermometer from Vicks lets you touch behind your child's ear and get a reading in one second. Babies (and parents) have never had it so easy.

Physicians, however, aren't ditching their tried-and-true methods. We checked in with Esther Krych, a Mayo Clinic pediatrician, to get the scoop on thermometer choices.

Rectal thermometers:

"The gold standard," says Krych. "It's the best way to get the core temperature in an infant. They're readily available and easy for parents to use."

Krych doesn't recommend using them beyond infancy, though. "Kids wiggle and the risk of injury is a little higher."

Rectal thermometers are available in both digital and mercury varieties. You should avoid taking your baby's temperature directly after a bath because the warm water could affect the temperature reading.

Oral thermometers:

You can attempt to take your child's temperature by mouth, but this can prove challenging with young children.

"Kids in preschool or younger have a hard time leaving their tongue over the thermometer," Krych says.

Better to go for an axillary reading (under the armpit), provided you have the proper method down from a medical professional.

If you're measuring an oral temperature, Krych says, wait 10-15 minutes after eating or drinking anything hot or cold.

Ear thermometers:

"When kids hit toddler age and up, an ear thermometer is the best way to get a good temperature," Krych says. "Their ear canals are large enough that you can get a tympanic properly in far enough."

No need to add a degree to a tympanic reading -- or any reading, for that matter. "Whatever you read is what the temperature is."

"In our clinic we do rectal or axillary for infants and tympanic for toddlers, and then we do tympanic for everybody, even adults."

Temporal thermometers:

"We don't really recommend temporal thermometers at all," Krych says. "They're popular, but they're not as well established for reading core temperature."

If a forehead swipe or behind-the-ear read says you have a fever, chances are you have a fever. But the temperature may not be accurate. "There's still not enough evidence that it actually works," Krych says.

(c) 2012 the Chicago Tribune Distributed by McClatchy-Tribune News Service.