Please choose the correct ending to complete the given sentence: Health: [header] How to lower a baby's fever [title] Take your baby's temperature rectally. [step] If you think your baby is running a fever, use a rectal thermometer to get the most accurate results. Place your baby on his or her stomach, or on his or her back with legs pulled up.

Ending1: [substeps] Older babies can be on an infant's rectum if this is appropriate. You could also check for a fever by using a thermometer designed for infants. Ending2: Coat the base of the thermometer with petroleum jelly, and insert it slowly into the anus-only about half an inch, so that the metal part is inside. Hold the thermometer still, and, when it beeps, remove it and read the results. Ending3: Hold your thermometer up to your baby's neck and take a measurement of your baby's temperature. Take the thermometer down to your baby's neck and record the number three-five-five. Ending4: If the thermometer is a digital thermometer, use it to help you get the most accurate measurement of your baby's temperature. [substeps] Call your local emergency service if your baby is under four years old, or if your baby is over two years old.

Answer format: ending1/ending2/ending3/ending4