At which time of the day would the nurse expect to obtain the lowest body temperature?

NSW Health

Hypothermia occurs when the body temperature is below 35°C. This can develop with prolonged exposure to temperatures under 10°C, or after prolonged immersion in cold water of less than 20°C.

A person with hypothermia may not be aware of their need for medical attention.

A body temperature below 32°C is life threatening.​​

Last updated: 04 February 2022

What is hypothermia?

• Hypothermia develops when the body temperature drops below 35°C. The normal human body temperature is around 37°C.
• As the body temperature drops below 32°C, hypothermia becomes severe and life threatening.

What are the symptoms?

• The first signs usually include feeling cold and uncontrollable shivering. If the person progresses into severe hypothermia, shivering usually stops.
• The person may feel exhausted and their skin may be cool and pale.
• As hypothermia advances, other symptoms include, fumbling hands, unsteady gait, slurred speech, confusion and drowsiness.
• Hypothermia can progress slowly and affected people may not be aware they need medical help.
• Symptoms of severe hypothermia include slowing of the heart rate and breathing, dilated pupils, and coma. The person may appear dead.
• With no treatment the condition is likely to lead to death.

How do you develop hypothermia?

• Hypothermia can develop with prolonged exposure to temperatures under 10°C, or after prolonged immersion in cold water of temperatures of less than 20°C..
• In colder conditions or when there is wind chill (the felt air temperature due to wind) it can occur within a shorter exposure.
• A person can be at greater risk of hypothermia as a result of some medical conditions.

Who is at risk?

Hypothermia can affect anyone, those at higher risk include:

• people over 75 years.
• babies and young children.
• people with poor circulation or diabetes.
• people with chronic physical or mental disabilities.
• people with underlying infection.
• people who are very thin and have low body fat.
• people who work outdoors.
• people who are homeless.
• people who are wet from any cause.

How is it prevented?

• Listen to the weather forecast.
• Plan ahead: schedule warm-up breaks for outdoor workers, hold recess and breaks inside, limit the amount of time you spend outdoors.
• Dress warmly in layers (wind-resistant jacket, mittens, boots, hat and scarf).
• Stay dry (wet clothing chills the body rapidly).
• Get out of the cold as soon as you can if you start feeling cold.
• Alcohol, cigarettes, caffeine and certain medications will increase your susceptibility to cold.
• Hypothermia can occur in the home: ensure there is adequate heating, especially for elderly people. Also, elderly people living on their own should consider wearing a personal emergency response system (PERS) as they are at risk of falls and hypothermia could develop if help is not at hand.
  

For parents and carers of children

• Young children and babies are at high risk from extreme cold and can develop hypothermia very quickly as their body size is so small. It is important to cover their head if they are out in cold weather.
• Children can become colder much quicker than adults because they have less muscle mass.
• Limit exposure to prolonged or extreme cold weather.

How is it diagnosed?

• The diagnosis is generally made based on the person's symptoms and the condition in which the person became unwell or was found. However, if the diagnosis is not obvious, it can be made by measuring the core body temperature with a special low-reading thermometer (general medical thermometers do not measure temperatures below 32-34°C).
• Mild hypothermia: 32-35°C.
• Severe hypothermia: below 32°C.

How is it treated?

• Get medical attention (call 000).
• Move the person out of the cold, remove wet clothing.
• Warm the person at the centre of the body (chest, neck, head, groin).
• Do not use direct heat; use warm blankets, towels, wrapped warm water bottles or skin to skin contact.
• Do not massage or rub the person.
• Keep the person still.
• If a person is awake, warm drinks can help.
• Do not give alcoholic beverages.
• If the person appears dead, CPR should be given whilst the person is being warmed - never assume the person is dead!

Further information

In NSW, call 1300 066 055 to talk to your local Public Health Unit​.​​

What are vital signs?

Vital signs are measurements of the body's most basic functions. The 4 main vital signs routinely checked by healthcare providers include:

• Body temperature

• Pulse rate

• Breathing rate (respiration)

• Blood pressure

Vital signs help detect or monitor medical problems. They can be measured in a medical setting, at home, at the site of a medical emergency, or elsewhere.

What is body temperature?

The normal body temperature of a person varies depending on gender, recent activity, food and fluid consumption, time of day, and, in women, the stage of the menstrual cycle. Normal body temperature can range from 97.8° F (36.5°C) to 99°F (37.2°C) for a healthy adult. A person's body temperature can be taken in any of the following ways:

• Orally. Temperature can be taken by mouth using a digital thermometer that uses an electronic probe to measure body temperature.

• Rectally. Temperatures taken rectally tend to be 0.5°F to 0.7°F higher than when taken by mouth. This is more common in babies because their body doesn't regulate temperature the way an older child or adult's body does.

• Armpit (axillary). Temperatures can be taken under the arm using a digital thermometer. Temperatures taken by this route tend to be 0.3°F to 0.4°F lower than those temperatures taken by mouth.

• By ear. A special thermometer can quickly measure the temperature of the eardrum, which reflects the body's core temperature (the temperature of the internal organs).

• By skin. A special thermometer can quickly measure the temperature of the skin on the forehead. Some thermometers don't require contact with the skin to get a temperature reading.

• Internally. This method is common in people who are critically ill in an intensive care unit. The temperature can be measured by probes that are placed in the esophagus, heart, or bladder.

Body temperature may be abnormal due to fever (high temperature) or hypothermia (low temperature). A fever is indicated when body temperature rises about 1 degree or more over the normal temperature of 98.6°F, according to the American Academy of Family Physicians. Hypothermia is defined as a drop in body temperature below 95°F.

Glass thermometers containing mercury

Exposure to mercury can be toxic and poses a threat to a person's health, as well as to the environment. Don't use glass thermometers with mercury, as they can break. If you have a mercury thermometer, dispose of it correctly in accordance with local, state, and federal laws. Contact your local health department, waste disposal authority, or fire department for information on how to correctly dispose of mercury thermometers.

What is the pulse rate?

The pulse rate is a measurement of the heart rate. This is the number of times the heart beats per minute. As the heart pushes blood through the arteries, the arteries expand and contract with the flow of the blood. Taking a pulse not only measures the heart rate, but also can indicate the following:

• Heart rhythm

• Strength of the pulse

The normal pulse for healthy adults ranges from 60 to 100 beats per minute. The pulse rate may fluctuate and increase with exercise, illness, injury, and emotions. Females ages 12 and older, in general, tend to have faster heart rates than do males. Athletes, such as runners, who do a lot of cardiovascular conditioning, may have heart rates near 40 beats per minute with no problems.

How to check your pulse

As the heart forces blood through the arteries, you feel the beats by firmly pressing on the arteries, which are located close to the surface of the skin at certain points of the body. The pulse can be found on the side of the neck, on the inside of the elbow, at the wrist, or in the groin. For most people, it's easiest to take the pulse at the wrist. If you use the lower neck, be sure not to press too hard. Never press on the pulses on both sides of the lower neck at the same time. This can block blood flow to the brain.

When taking your pulse:

• Using the first and second fingertips, press firmly but gently on the arteries until you feel a pulse.

• Start counting the pulse when the clock's second hand is on the 12.

• Count your pulse for 60 seconds (or for 30 seconds and then multiply by 2 to calculate beats per minute).

• When counting, don't watch the clock continuously, but concentrate on the beats of the pulse.

• If unsure about your results, ask another person to count for you.

If your healthcare provider has asked you to check your own pulse and you are having trouble finding it, consult your provider or nurse for additional instruction. Many types of monitoring devices can help check your pulse. These include fitness tracker devices to help track your pulse rate.

What is the respiration rate?

The respiration rate is the number of breaths you take each minute. The rate is usually measured when you are at rest. It simply involves counting the number of breaths for one minute by counting how many times your chest rises. Respiration rates may increase with exercise, fever, illness, and with other medical conditions. When checking respiration, it's important to also note whether you have any trouble breathing.

Normal respiration rates for an adult person at rest range from 12 to 20 breaths per minute.

What is blood pressure?

Blood pressure is the force of the blood pushing against the artery walls during contraction and relaxation of the heart. Each time the heart beats, it pumps blood into the arteries. It results in the highest blood pressure as the heart contracts. When the heart relaxes, the blood pressure falls.

Two numbers are recorded when measuring blood pressure. The higher number is called systolic pressure. It refers to the pressure inside the artery when the heart contracts and pumps blood through the body. The lower number is called diastolic pressure. It refers to the pressure inside the artery when the heart is at rest and is filling with blood. Both pressures are recorded as "mm Hg" (millimeters of mercury).  

High blood pressure directly increases the risk of heart attack, heart failure, and stroke. With high blood pressure, the arteries may have an increased resistance against the flow of blood. This causes the heart to work harder to circulate the blood.

Blood pressure is categorized as normal, elevated, or stage 1 or stage 2 high blood pressure:

• Normal blood pressure is systolic of less than 120 and diastolic of less than 80 (120/80)

• Elevated blood pressure is systolic of 120 to 129 and diastolic less than 80

• Stage 1 high blood pressure is systolic is 130 to 139 or diastolic between 80 to 89

• Stage 2 high blood pressure is when systolic is 140 or higher or the diastolic is 90 or higher

These numbers should be used as a guide only. A single blood pressure measurement that is higher than normal does not necessarily mean there is a problem. Your healthcare provider will want to see multiple blood pressure measurements over several days or weeks before making a diagnosis of high blood pressure and starting treatment. Ask your provider when to contact him or her if your blood pressure readings are not within normal range.

Why should I monitor my blood pressure at home?

For people with high blood pressure, home monitoring allows your healthcare provider to monitor how much your blood pressure changes during the day, and from day to day. This may also help your provider determine how effectively your blood pressure medicine is working.

What special equipment do I need to measure blood pressure?

You can use either an aneroid monitor, which has a dial gauge and is read by looking at a pointer. Or you can use a digital monitor, in which the blood pressure reading flashes on a small screen. Whichever device you use, make sure the cuff fits your arm. Having a cuff that is too large or too small can lead to inaccurate readings.

Don't take your blood pressure on an arm or leg that has been severely injured, has had surgery on the blood vessels, or has injury to the tissue.

Before you measure your blood pressure

The American Heart Association recommends the following guidelines for home blood pressure monitoring:

• Don't smoke, have caffeinated drinks, or exercise for 30 minutes before taking your blood pressure.

• Go to the bathroom before the test.

• Relax for 5 minutes before taking the measurement.

• Sit with your back supported (don't sit on a couch or soft chair). Keep your feet on the floor uncrossed. Place your arm on a solid flat surface (like a table) with the upper part of the arm at heart level. Place the middle of the cuff directly above the bend of the elbow. Check the monitor's instruction manual for an illustration.

• Take multiple readings. When you measure, take 2 to 3 readings one minute apart and record all the results.

• Take your blood pressure at the same time every day, or as your healthcare provider recommends.

• Record the date, time, and blood pressure reading.

• Take the record with you to your next medical appointment. If your blood pressure monitor has a built-in memory, simply take the monitor with you to your next appointment.

• Call your provider if you have several high readings. Don't be frightened by a single high blood pressure reading, but if you get several high readings, check in with your healthcare provider.

• If your blood pressure reaches a systolic (top number) of 180 or higher OR diastolic  (bottom number) of 110 or higher, seek emergency medical treatment.

Ask your  healthcare provider to teach you how to use your blood pressure monitor correctly. Have the monitor routinely checked for accuracy by taking it with you to your healthcare provider's office. It's also important to make sure the tubing is not twisted when you store it and keep it away from heat to prevent cracks and leaks. Monitors will have to be replaced now and then. Check that your device is working correctly.

Proper use of your blood pressure monitor will help you and your healthcare provider in monitoring your blood pressure.

Which site for taking the body temperature is considered to give the most accurate results?

When obtaining an oral temperature on a client the nurse inserts the thermometer?

What is the order in which the nurse should perform vital signs?

What should the nurse do if the client temperature is not normal?