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Normal Body Temperature & Body Temp Ranges To Be Concerned With

Illustration of a woman holding her head while taking her temperature with a thermometer

Introduction & Summary

Your body temperature is considered a “vital sign” because it is an important indicator of your body’s status. Normally body temperature is 98.6° F (37° C) but can vary slightly based on different factors. You should seek immediate medical attention if your temperature is below 95° F (35° C) or above, if you have had your fever for more than a few days, if you have other significant medical problems and a fever above 100.4° F (38° C) , or if you are feeling very unwell because of your fever or the associated symptoms.

In this article we’ll explore:

What Is Normal Body Temperature For Adults & Kids?

Body temperature is one of our “vital signs,” along with heart rate, blood pressure, and breathing rate. They are called “vital” because they are important indicators of our body’s status, and can serve as important warning signs if there is something wrong with your body.

The normal human body temperature is 98.6° F (37° C) and the body is very good at maintaining this temperature. However, this value can vary slightly based on different factors like:

  • Age
  • Gender
  • Body size
  • Where you measure the temperature (under the tongue, at the other end of your gastrointestinal tract, under the armpit, etc.)
  • Time of day
  • Outside conditions
  • Whether you recently did something active, such as working out
  • Any illness like an infection (that’s why we reach for the thermometer when we aren’t feeling well)

What Body Temperature Is Too Low?

Some people have a naturally low body temperature that is less than 98.6° F (37° C). Subnormal body temperature can also be caused by certain medical conditions, including an infection. Hypothermia is a medical emergency in which the body temperature drops dangerously low, below 95° F (35° C). This condition usually results from prolonged exposure to cold or being submerged in cold water, at which point the body begins to lose more heat than it can generate.

At temperatures below 95° F (35° C), the body’s different organ systems cannot function properly. Untreated, this can result in organ failure and even death.

When To Seek Care For A Low Body Temperature

If you measure a body temperature below 95° F (35° C), you should seek medical care immediately. In the case of babies and young children, a body temperature of less than 97° F (36.1° C) is a cause to seek immediate medical evaluation.

What Temperature Is A Fever?

Some people have a normal body temperature that is somewhat higher than 98.6° F (37° C). The body temperature can rise further in response to certain conditions, such as an infection. Any temperature between 98.6-100.4° F (37-38° C) is considered a low-grade fever. Temperatures above 100.4° F (38° C) are considered a fever. A fever by itself is not necessarily a bad thing and may mean that the body’s immune system is fighting against an infection. This is a normal response.

You can treat fever by taking over-the-counter medications like acetaminophen (Tylenol) or ibuprofen (Motrin or Advil), and by drinking plenty of fluids.

When to Seek Care For A Fever

However, if you are an adult with other significant medical conditions or if your temperature is higher than 103° F (39.4° C), seek medical care. If your child is less than three months old and has any fever, or if you or your child has had your fever for more than a few days, you should seek medical attention.

Easy-To-Read Body Temperature Chart

For healthy adults and kids without other underlying health issues, here’s an easy-to-read chart that shows what various body temperatures mean and when to seek care. For the purpose of this chart, all measurements are made by mouth, with the thermometer under the tongue.

Body Temperature Chart

If you have other chronic health conditions, a fever could mean a different course of action. Talk to your doctor about what to watch for and when to seek care.

How Body Temperature Can Affect Common Medical Conditions

Having a fever can be more problematic for people with certain common medical conditions. In particular, people with chronic medical conditions may experience a worsening of their baseline symptoms in response to a fever or the underlying infection. For instance, any respiratory infection can lead to worse symptoms for people with asthma, other chronic breathing problems, and certain heart problems, including congestive heart failure.

There are other common medical conditions which may make it harder for your body to fight off an infection, including diabetes and cancer. If you have these medical conditions and a fever, you should have a lower threshold to contact your doctor since you are at increased risk for complications.

Tips on How to Regulate Body Temperature

When exposing your body to extreme conditions, you should think ahead about ways to help your body regulate body temperature to avoid some of the serious complications mentioned above. Especially if you’re fighting an infection, it’s a good idea to give your body some extra support.

In cold weather, this means:

  • Bundle up! Wear multiple layers, including gloves and a warm hat
  • Spend as little time as possible in the cold

In hot weather, this means:

  • Drink plenty of water, as your body loses extra fluid as it tries to keep cool
  • Try to avoid prolonged exposure to the sun
  • Take frequent breaks if doing something active and wear breathable, lightweight clothing

Are You Concerned About Your Body Temperature?

When taking your temperature at home, you can choose from an oral, rectal, ear or forehead thermometer. Always use a digital thermometer and follow the instructions. If you don’t have a thermometer available, you may suspect a fever if you are having chills, shivering, sweating or feeling clammy. You may also notice that your cheeks are red. You could treat your fever by taking medications like acetaminophen (Tylenol) or ibuprofen (Motrin or Advil), and by drinking plenty of fluids.

Four Reasons To Seek Medical Care For A Fever

In terms of when to seek medical care, you should always use your judgement and seek medical care if you think your condition is serious, or if you meet any of the following criteria if:

  • You’re an adult with a temperature higher than 103° F (39.4° C), or if you have significant medical conditions and any fever greater than 100.4° F (38° C)
  • You or your child has had your fever for more than a few days
  • Your child is less than three months with any fever greater than 100.4° F (38° C)
  • If you feel very unwell because of your fever, or because of the associated symptoms

How K Health Can Help

If you have a fever and it’s not an emergency, you can check your symptoms with K Health and get more information that could help you make a decision. Did you know you can get affordable primary care with the K Health app? Download K to check your symptoms, explore conditions and treatments, and if needed text with a doctor in minutes. K Health’s AI-powered app is HIPAA compliant and based on 20 years of clinical data.

Edo Paz, MD

Edo Paz is the VP of Medical at K Health. Dr. Paz has two degrees in chemistry from Harvard and an MD from Columbia University. He did his medical training in internal medicine and cardiology at New York-Presbyterian. In addition to his work at K Health, Dr. Paz is a cardiologist at Heartbeat Health, a cardiology practice located in New York City.