[header] How to check vitals [title] Pick a thermometer. [step] 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. [substeps] For babies under 3 months, always use a digital or glass thermometer to take a rectal reading.