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Fever (Body Temperature Measurement)

Published: August 9, 2026Updated: August 16, 2026

This test measures your core body temperature to determine if it is elevated above normal levels, which may indicate an infection, inflammation, or other underlying condition.

Quick summary

["Elevated body temperature can signal a need for further medical evaluation."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
28385-3
Short code
FEVER
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
reported-hiv-ssc
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is a Fever Test Done?

Doctors may order a fever test if you have symptoms like chills, sweating, fatigue, or unexplained pain. It helps identify whether your body is fighting an infection, responding to an illness, or experiencing a systemic condition that requires treatment.

What Does a Fever Test Involve?

This test is typically done by taking your oral, rectal, or axillary (underarm) temperature using a thermometer. No special preparation is needed, but it’s important to note that oral temperatures can be slightly lower than core temperatures.

What Are Common Causes of a Fever?

Fever can result from infections (like colds, flu, or bacterial infections), illnesses such as COVID-19 or the flu, inflammatory conditions, or even certain medications. It’s a natural response to help your immune system fight off pathogens.

What Does a Fever Mean for My Health?

A fever alone doesn’t always mean you’re sick, but it can be a sign that your body is responding to an infection or illness. If your fever is high (above 101°F/38.3°C) or lasts more than a few days, it’s important to discuss it with your healthcare provider to rule out serious conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Body Temperature Check

Frequently asked questions

What should I expect from my results?
If your test shows a fever, your healthcare provider may recommend additional tests (like bloodwork, imaging, or cultures) to determine the cause. Normal body temperature ranges can vary slightly, so results are interpreted in the context of your overall health and symptoms.
How long should I wait to see if my fever goes away?
Most fevers resolve within a few days as your body fights the infection. If your fever persists beyond 3–4 days, or if you develop other concerning symptoms (such as severe headache, confusion, or difficulty breathing), seek medical attention promptly.
Can I take medication to lower my fever before seeing a doctor?
Yes, over-the-counter fever reducers like acetaminophen or ibuprofen can help manage symptoms temporarily. However, avoid self-medicating if you have underlying health conditions or are unsure about safe dosages. Always consult your doctor before using medications.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy