Body Temperature: Which Values are Normal?

The body temperature of a human being says a lot about his state of health. We explain what is normal and what else you should know.

Why is our body temperature so important?

In order for our body to function properly and for all metabolic processes to run smoothly, we need a special body temperature. However, this so-called body core temperature is never exactly the same – it is influenced by various factors and therefore fluctuates slightly. If the body is healthy, it can also regulate the temperature itself – for example, it drops with the help of cooling sweat.

What body temperature is normal for humans?

An adult should normally have a body temperature of between 36.5 and 37.4 degrees – from 37.5 degrees there is a slightly elevated temperature, from 38 degrees Celsius onwards one speaks of fever. The core temperature varies slightly from person to person. In babies and toddlers the body temperature is generally slightly higher than in adults: Newborns, for example, have a general body temperature of 37.5 degrees. The little ones’ bodies are not yet able to regulate the heat balance optimally, and children sweat less than adults. This means that their temperature is more susceptible to fluctuations, and fever is also more frequent.

Standard values of human body temperature

The following guide values apply to body temperature in humans:

• Slightly elevated temperature: 37.5 to 38 degrees Celsius
• Mild fever: 38 to 38.5 degrees Celsius
• Moderate fever: 38.6 to 39 degrees Celsius
• High fever: 39.1 to 39.9 degrees Celsius
• Very high fever: 40 to 40.9 degrees Celsius
• Extreme fever: 41 degrees Celsius and higher

Body core temperature or surface temperature?

In science, a distinction is made between the body core temperature and the surface temperature:

• Core body temperature: It is approximately 37 degrees, but is subject to minimal fluctuations (e.g. due to circulatory problems). The core body temperature ensures that the internal organs are supplied with sufficient heat.
• Surface temperature: Also called shell temperature – it refers to the values on the skin and limbs. The surface temperature is subject to much greater fluctuations than the body core temperature due to the outside temperatures and is usually much lower than this.

Body temperature fluctuations: What are the causes?

That the body temperature varies slightly from measurement to measurement can happen for different reasons. The following factors influence the temperature:

• Hormonal fluctuations in women: One to two days after ovulation, the body temperature of women increases by about 0.5 degrees.
• Time of day: The normal temperature is highest in the afternoon due to metabolic processes – it is often up to one degree higher than in the morning. Afterwards it drops again.
• Emotions: Our emotions also influence body temperature – emotions caused by psychological stress, for example, increase it.
• Physical activity: During heavy physical stress the temperature can rise up to 40 degrees.
• Illnesses: Various forms of cancer and hyperthyroidism can also increase the body temperature.

In addition, age, diet and the intake of various drugs also play a role in temperature.

What happens if our body temperature is too low or too high?

Slightly changed values that deviate from the norm can usually be tolerated quite well by a healthy body. Extreme temperatures, however, are harmful to it:

• Temperatures above 41 degrees Celsius stress the circulation and can damage both tissue and organs. If the temperature rises to 42.6 degrees, there is danger to life.
• Temperatures below the normal temperature (undertemperature) ensure that the body throttles the organism – oxygen consumption is reduced, metabolic processes are inhibited. The cause of this can be, for example, an excessively cold ambient temperature, but various illnesses such as hypothyroidism can also promote undertemperature. If a temperature below 28 degrees (“hypothermia”) is measured, the pulse and breathing are slowed down, and there is a risk of circulatory failure and respiratory arrest.

You want more information on body temperature? Find out here which home remedies help against fever.