Normal body temperature for adults, babies, during pregnancy, and more

Normal body temperature for adults, babies, during pregnancy, and more

The Wonders of Body Temperature: Understanding the Variation and Significance

Body Temperature

Body temperature is a fascinating aspect of human physiology. We all know that the average adult body temperature is around 98.6°F (37°C), but did you know that individual baseline body temperatures can vary? Factors such as age and activity levels can affect a person’s normal body temperature. Even the way we measure temperature can have an impact on the reading.

Body temperature readings can vary depending on where the measurement is taken on the body. For example, rectal temperature readings tend to be higher than oral readings, while armpit readings tend to be lower. But there are other factors that can also influence body temperature readings. Age, time of day, recent activity, and even food and fluid intake can all play a role in determining a person’s temperature.

Normal Temperature Ranges

Before we delve deeper into the fascinating world of body temperature, let’s take a look at the typical temperature ranges for different demographics.


According to reviews, the average adult body temperature across all different reading sites is 97.86°F (36.59°C). When taken orally, the average adult body temperature falls between 97.2–98.6°F (36.24–37°C). However, it’s important to note that average body temperature can vary across demographics.

A study of almost 35,500 people found that older adults had lower temperatures, while African American women had higher temperatures than white men. Furthermore, certain medical conditions can affect body temperature. For example, people with an underactive thyroid (hypothyroidism) tend to have lower temperatures, while people with cancer have higher temperatures.

If your temperature reaches at least 100.4°F (38°C), it suggests that you have a fever. A temperature above 103.1°F (39.5°C) is considered a high fever, and anything above 105.8°F (41°C) is categorized as a very high fever. It’s important to be aware that a fever can also be a symptom of COVID-19.


The average body temperature for children is around 97.52°F (36.4°C), but this can vary. Similar to adults, a temperature above 100.4°F (38°C) in children may indicate a fever.


Newborn babies tend to have higher body temperatures than older children and adults. The average body temperature for newborns is around 99.5°F (37.5°C). This is because babies have a larger body surface area relative to their body weight, and their bodies are more metabolically active, generating more heat. However, babies’ bodies do not regulate temperature as effectively as adults’, which can make it challenging for them to cool down during a fever.


During pregnancy, a person’s basal metabolic rate (BMR) increases, resulting in the production of more heat. One study found that body temperature peaks at 96–99.5°F (35.6–37.5°C) around the 12th week of pregnancy. The average body temperature reaches its lowest point of around 95.5–99.1°F (35.3–37.3°C) just after the 33rd week.

How to Measure Temperature

There are various types of thermometers available for measuring body temperature.

Digital Thermometers

Digital thermometers are widely used and produce accurate results. They can be used for measuring temperature at different parts of the body:

  • Rectal measurement: Specialized digital rectal thermometers are commonly used for young children. It is essential to clean and lubricate the device before inserting it into the anus. The device will alert when the reading is complete and safe to remove.

  • Oral measurement: Standard digital thermometers are easy to use orally. The tip of the device must be clean, and it should be placed under the tongue toward the back of the mouth. The device will display the temperature reading.

  • Axillary (armpit) measurement: A digital thermometer can be placed in the armpit to measure temperature. The arm must remain firmly against the body for an accurate reading. This is a noninvasive and convenient option for measuring a child’s temperature.

Infrared Thermometers

Infrared thermometers can measure temperature at a distance, but they are less accurate compared to other methods. Tympanic thermometers can be used to measure temperature from the ear canal. To use them, insert the tip into the ear and align it with the ear canal. Activate the device to obtain a reading.

Temporal thermometers use an infrared signal to measure temperature. They are held a few centimeters from the forehead, and the device will produce a reading. Although forehead and ear measurements are viable options, rectal measurements are still considered the most accurate for infants.

Instructions provided with the thermometer always need to be followed to ensure accurate results.

When Temperature is Too High or Too Low

If a thermometer indicates that a person’s body temperature is too high or too low, it is advisable to take another reading to confirm the result. In many cases, a high temperature may be a result of a short-term illness and usually does not cause significant harm in adults with good overall health. Resting and staying hydrated can help manage a high temperature. These measures also apply to children and babies.

Sometimes, hyperthermia can occur in hot climates or during intense physical activity. Unlike a fever caused by an infection, this is usually the result of external factors. Cooling down by moving to a cooler space and staying hydrated can help alleviate hyperthermia. However, if a high temperature persists or increases, it is crucial to seek medical help.

On the other hand, if a person’s temperature drops below 95°F (35°C), they may have hypothermia and should seek immediate medical assistance.

When to Seek Medical Assistance

The need for medical assistance may vary depending on age groups.


In many cases, a person with a fever does not require medical attention. However, it is important to contact a doctor if a fever reaches or higher. Additionally, if a person experiences dehydration, lightheadedness, severe cramps, or a persistent or worsening fever, seeking medical assistance is advised.

People with certain conditions such as recent transplant recipients, compromised immune systems, individuals on immunosuppressants, or those who have recently undergone cancer treatments should also seek medical help if they experience a fever.

If a person’s temperature exceeds 106.7°F (41.5°C), they have hyperpyrexia, which is a medical emergency requiring urgent medical assistance. Conversely, if a person’s body temperature falls below 95°F (35°C), they may have hypothermia, which also requires immediate medical attention.


In the case of children, emergency services should be contacted if a child has a temperature over 104°F (40°C). Medical help should also be sought if a child has a high temperature that lasts for 5 days or more, or if they are experiencing dehydration, vomiting, or diarrhea. If a child’s temperature drops below 95°F (35°C), medical assistance is essential.


For babies aged 3 months or younger, emergency medical attention is required if their temperature is 100.4°F (38°C) or above. In infants up to 6 months old, a temperature of 102.2°F (39°C) or more is another indicator for seeking emergency services. Similarly to adults and older children, if a baby’s temperature drops below 95°F (35°C), they should receive immediate emergency assistance.

What Causes Body Temperature to Change?

The hypothalamus, a region of the brain, plays a significant role in regulating body temperature. If the body’s temperature goes above or below the 98.6°F (37°C) mark, the hypothalamus initiates mechanisms to regulate it.

When the body is too cold, the hypothalamus triggers shivering to generate heat. When the body is too hot, it signals the body to sweat, facilitating heat loss. Infections are the most common cause of fevers. Fever is the body’s natural defense mechanism to fight off infections.

Symtoms of a Fever

Considered a fever when the body temperature reaches or exceeds 100.4°F (38°C), other symptoms include appetite loss, chills, headache, irritability, muscle aches, shivering, sweating, and weakness.

In Summary

The ideal body temperature for adults is around 98.6°F (37°C), but it can vary based on factors such as age, physical activity, and health. Babies may have higher body temperatures than adults. Even a slight fever in babies can indicate a severe infection.

Different body parts yield a range of body temperatures that doctors consider normal. Rectal readings are higher than oral readings, while armpit readings tend to be lower. It is crucial to seek medical attention if you have an unusually high or low temperature.

Remember that variations in body temperature are a normal part of our physiology, and seeking medical assistance when necessary ensures proper care and well-being. Stay informed, stay healthy!

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