Fever Temperature: 5 Key Facts About High and Low Body Temperature
What body temperature is considered a fever is a common question. Basically, when body temperature rises above the normal body temperature, it is considered a fever. Fever is not a disease; it is a sign that the body is fighting an infection. If your body temperature goes up, it may mean that your immune system is fighting against bacteria or viruses.
Many people consider 98.6°F (37°C) to be a normal body temperature. But, normal body temperature can vary from person to person, and it may change throughout the day. For example, body temperature is usually lower in the morning and higher in the evening.
Moreover, temperature can vary depending on how it is measured, so it is very important to use the correct fever range for your thermometer type.
What is Low Grade Fever Temperature
Low grade fever means that slight increase in body temperature, usually low grade fever measures between 99°F and 100.4°F (37.2°C to 38°C). If the low grade fever lasts for more than 24 hours, it may be considered persistent. If the low grade fever continues for 10 to 14 days or longer, it is called a chronic fever.
Mostly, low grade fevers are not that much serious, and they are usually caused by common infections like cold or flu. That may be a sign that your immune system fights against the virus or bacteria.
In some cases, especially in people with a weakened immune system or an autoimmune disease, medical attention may be needed because, in some cases, low grade fever can be caused by other health conditions.
When to see a doctor
Infants
For babies, especially those younger than 3 months old, even a slight fever can be considered a serious infection. You should definitely contact a medical professional if the baby,
- Seems unusually irritable or uncomfortable
- Is very sleepy or difficult to wake
- Has diarrhea, a cold, or a cough
- Has a fever that lasts more than 3 days
Children
Low grade fever in children is usually not serious if the child
- Making eye contact
- Drinking fluids
- Playing normally
Please contact a medical professional if the low grade fever lasts for more than 3 weeks or if the child
- Is very irritable or uncomfortable
- Has poor eye contact
- Vomits repeatedly
- Has severe diarrhea
- Develops a fever after being left in a hot car
Adults
Usually low grade fever in adults is that much concern, unless it rises above 103°F (39.4°C). But you should contact medical professional if
- Your fever is higher than 103°F (39.4°C)
- Your fever lasts more than 3 days, even if it is lower than 103°F
And contact medical professional if you have
- A rash that spreads quickly
- Persistent vomiting or Pain while urinating
- seizures or a stiff neck
- A severe headache or difficulty breathing
- Muscle weakness
What is High Grade Fever Temperature
Usually, a high-grade fever is considered when the body temperature rises to 103°F (39.4°C) or higher. You should also be aware and alert if a fever stays above 100°F (37.8°C) for an unusually long time, as it may indicate an underlying health problem.
When to see a doctor
Children and Infants
Children and infants have different temperature limits than adults. If the temperature reaches 100.4°F (38°C) or higher, babies, especially those younger than 3 months, should be seen by a doctor immediately.
If the temperature reaches 102°F to 103°F (38.9°C to 39.4°C) in older children and lasts for a long time or does not improve after taking fever-reducing medicine, it may require urgent medical attention. You should also contact a doctor if your child has a fever along with:
- Vomiting
- A rash
- Unusual sleepiness
- Difficulty waking up
- Any other concerning symptoms
Adults
- Your fever reaches 103°F (39.4°C) or higher
- The fever lasts for several days
- Symptoms continue to worsen
- You experience difficulty breathing and confusion
- severe headache, dehydration, or other concerning symptoms
How to Check Your Body Temperature
- Turn on the digital thermometer.
- Move the thermometer across your forehead.
- Wait for the thermometer to complete the reading.
- Read the temperature displayed on the screen.
Armpit Temperature
- Turn on the digital thermometer.
- Place the tip of the thermometer under your armpit, making sure it touches the skin.
- Keep your arm pressed firmly against your body until the thermometer beeps.
- Remove the thermometer and read the temperature displayed on the screen.
FAQs
What is the best way to check an infant’s body temperature?
Taking a rectal temperature using a digital thermometer is the most accurate way to check an infant’s body temperature.
What care is required to keep a digital thermometer safe?
- Clean it before and after each use.
- Store it in its protective case in a cool, dry place.
- Check the battery regularly and replace it when needed.
Why does fever temperature vary when measured using different methods?
- Fever temperature may vary as per different body parts.
- Some areas like the rectum are closer to the body’s core temperature, so it usually gives a higher temperature.
- Some areas like the armpit are cooler, so it may give a lower temperature.
- Some conditions like room temperature, sweat, and recent eating; in such conditions, thermometer accuracy can also be affected.
References
Cleveland Clinic – Fever Temperature Over view
Healthline – Low Grade Fever and High Grade Fever
Mayo clinic – How to check your Body Temperature
Conclusion
When body temperature rises above the normal body temperature, it is considered a fever. Fever is not a disease; it is a sign that the body is fighting an infection. Many people consider 98.6°F (37°C) to be a normal body temperature. But, normal body temperature can vary from person to person, and it may change throughout the day.
Low grade fever means that slight increase in body temperature, usually low grade fever temperature measures between 99°F and 100.4°F (37.2°C to 38°C). A high grade fever is considered when the body temperature rises to 103°F (39.4°C) or higher.
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