This is a test of commonsense. Complete the next sentence:

How to check vitals 
Pick a thermometer. 
To take someone's temperature, you have several options when it comes to thermometers. Glass or digital thermometers can be used orally, rectally, and under the armpit.
Special thermometers can be used on the forehead (skin) or in the ear. For babies under 3 months, always use a digital or glass thermometer to take a rectal reading.