the range of 36.0 °C to 37.5 °C (96.5–99.5 °F). The main reason for checking body temperature is to solicit any signs of systemic infection or inflammation in the presence of a fever. Fever is considered temperature of 37.8 °C or above. Other causes of elevated temperature include hyperthermia, which results from unregulated heat generation or abnormalities in the body's heat exchange mechanisms. Temperature depression (hypothermia) also needs to be evaluated. Hypothermia is classified as temperature below 35 °C (95 °F). It is also recommended to review the trend of the patient's temperature over time. A fever of 38 °C does not necessarily indicate an ominous sign if the patient's previous temperature has been higher. Pulse The pulse is the rate at which the heart beats while pumping blood through the arteries, recorded as beats per minute (bpm). It may also be called "heart rate". In addition to providing the heart rate, the pulse should also be evaluated for strength and obvious rhythm abnormalities. The pulse is commonly taken at the wrist (radial artery). Alternative sites include the elbow (brachial artery), the neck (carotid artery), behind the knee (popliteal artery), or in the foot (dorsalis pedis or posterior tibial arteries). The pulse is taken with the index finger and middle finger by pushing with firm yet gentle pressure at the locations described above, and counting the beats felt per 60 seconds (or per 30 seconds and multiplying by two). The pulse rate can also be measured by listening directly to the heartbeat using a stethoscope. The pulse may vary due to exercise, fitness level, disease, emotions, and medications. The pulse also varies with age. A newborn can have a heart rate of 100–⁠160 bpm, an infant (0–⁠5 months old) a heart rate of 90–⁠150 bpm, and a toddler (6–⁠12 months old) a heart rate of 80–140 bpm. A child aged 1–⁠3 years old can have a heart rate of 80–⁠130 bpm, a child aged 3–⁠5 years old a heart rate of 80–⁠120 bpm, an older child (age of 6–10) a heart rate of 70–⁠110 bpm, and an adolescent (age 11–⁠14) a heart rate of 60–105 bpm. An adult (age 15+) can have a heart rate of 60–100 bpm. Respiratory rate Average respiratory rates vary between ages, but the normal reference range for people age 18 to 65 is 16–20 breaths per minute. The value of respiratory rate as an indicator