Is it good to shiver when sick? Understanding the body's fever response

September 24, 2025 •

4 min read

When your body detects an infection, your immune system triggers a rise in your core temperature to create an inhospitable environment for pathogens. This often includes muscle contractions known as shivering. So, is it good to shiver when sick? This common reaction is actually a sign that your body is actively fighting back.

Quick Summary

Shivering when you are sick is a normal and often necessary part of your body’s immune response, as it helps raise your core temperature to create a less favorable environment for viruses and bacteria. The involuntary muscle contractions generate heat to match the brain’s new, higher temperature set-point during a fever. It is a sign that your body is engaged in a powerful defense mechanism.

Key Points

Normal immune response: Shivering when you're sick is a healthy and natural part of your body's immune system fighting infection.
Fever's purpose: The involuntary muscle contractions help raise your core body temperature, which can hinder the growth of many viruses and bacteria.
Feeling cold paradox: You feel cold during a fever because your brain has reset its internal 'thermostat' to a higher temperature, and your current temperature feels low by comparison.
Management is key: For mild fevers, focus on rest, hydration, and comfort measures like light blankets, avoiding excessive bundling that can dangerously increase fever.
Seek medical advice when necessary: If shivering is accompanied by a very high fever (above 103°F in adults), confusion, or other severe symptoms, it is important to contact a healthcare professional.

The Science Behind Your Chills

Shivering is an involuntary physiological response designed to generate heat and help your body reach a new, higher temperature set-point. When you have a fever, your immune system releases substances called pyrogens, which act on the hypothalamus—the body’s thermostat in the brain. The hypothalamus then raises the body’s target temperature. To meet this new, higher temperature, your body starts to generate heat by causing your muscles to contract and relax rapidly, which is the shivering you feel.

While uncomfortable, this process is generally beneficial. Many pathogens, including bacteria and viruses, thrive best at normal body temperature. By raising the body's temperature, the immune system aims to slow down the reproduction rate of these germs, giving your immune cells a better chance to mount an effective counter-attack. The shaking is therefore an essential part of the fever, not a side effect to be feared, unless it is accompanied by other severe symptoms or the fever reaches a dangerous level.

Why You Feel Cold When You Have a Fever

It might seem counterintuitive to feel cold and shiver when your body temperature is actually rising, but this sensation is a direct result of your hypothalamus's reset. Once your brain sets a new, higher thermostat setting (e.g., 102°F), your normal body temperature (98.6°F) feels cold by comparison. Your body's response is to warm up, triggering the shivering response. This is why you may feel like bundling up with extra blankets, but doing so is often discouraged, as it can trap heat and cause the fever to spike even higher. The shivering will typically subside once your body reaches the new temperature set-point.

When is Shivering a Cause for Concern?

While a normal part of the immune response, shivering can sometimes indicate a more serious issue. It’s important to monitor your symptoms and know when to seek professional medical advice. Conditions like meningitis, severe infections, or a high fever that won't come down with at-home care warrant medical attention.

Extremely high fever: A fever over 103°F (39.4°C) in adults or over 101°F (38.3°C) in infants is often a red flag.
Inability to be consoled: In children, inconsolable crying or severe irritability with a fever should be addressed.
Accompanying symptoms: Other alarming symptoms include a stiff neck, severe headache, confusion, shortness of breath, or a rash.
Prolonged duration: A fever and chills that do not improve after a few days should be evaluated by a healthcare provider.

How to Manage Fever and Chills at Home

For mild to moderate fevers and related shivering, there are several steps you can take to manage your symptoms and feel more comfortable. It is crucial to focus on supporting your body’s natural processes without interfering too much.

Stay hydrated. Drink plenty of fluids like water, electrolyte drinks, or clear broths. Dehydration can exacerbate fever symptoms and is a risk with any illness.
Rest. Giving your body the energy it needs to fight the infection is critical. Rest is essential for a strong immune response.
Use over-the-counter fever reducers. Medications like acetaminophen or ibuprofen can help lower your fever and reduce discomfort from chills, but consult a doctor before giving medication to children.
Try a lukewarm sponge bath. Gently sponging your body with lukewarm water can help cool you down. Avoid cold water or ice baths, as this can trigger more intense shivering.
Wear light clothing. Opt for a single layer of clothing or light blankets. While you may feel cold initially, excessive bundling can cause your temperature to rise unnecessarily.

Shivering During Sickness: A Comparison


Feature	Shivering with a Fever	Shivering from Cold Exposure
Cause	Your brain resetting its temperature target higher due to infection.	Your body trying to warm up from external cold temperatures.
Temperature	Your body temperature is actually high and rising.	Your body temperature is low and needs to be raised.
Feeling	You feel cold relative to your new, higher set-point.	You feel cold relative to your normal set-point.
Action	A sign your immune system is working to fight pathogens.	A response to environmental conditions.

Conclusion: Listening to Your Body

In most cases, shivering while sick is a normal and functional part of your body’s fight against illness. It’s a powerful tool your immune system uses to create a less-friendly environment for invading pathogens. For a mild fever, managing the chills with proper hydration and rest is the best course of action. However, awareness is key. If you or a loved one experience extreme fevers or other worrying symptoms, seeking professional medical advice is essential. The U.S. National Library of Medicine provides excellent resources on fever and chills, reminding us that understanding our body's signals is the first step toward better health (https://medlineplus.gov/ency/article/003091.htm). Always prioritize safety and listen to what your body is telling you.

Frequently Asked Questions

Not necessarily. Shivering indicates that your body is trying to raise its temperature to a new set-point established by your brain. It's a sign that the fever process is actively working, but it doesn't automatically mean the fever is intensifying or becoming more dangerous. What's most important is the severity of the fever itself and any other symptoms you might have.

The terms are often used interchangeably. Chills refer to the sensation of feeling cold, often accompanied by shivering. Shivering is the physical, involuntary muscle contraction that generates heat. The chills are the feeling, and the shivering is the action your body takes to overcome that feeling.

It is best to stay comfortable without bundling up too much. While you may feel cold and want to pile on blankets, this can trap heat and cause your fever to rise even higher. Use a light blanket and dress in a single layer to allow your body to regulate its temperature more effectively.

Trying to stop shivering can interfere with your body's natural defense mechanism. Instead of preventing it, it is more effective to manage the fever itself. Use over-the-counter fever reducers if appropriate and focus on resting and staying hydrated to support your body's immune response.

You should seek medical advice if your fever is very high (above 103°F in adults), if the fever and chills last for more than a few days, or if they are accompanied by other severe symptoms like a stiff neck, confusion, or severe headache. For infants under three months, any fever warrants a doctor's visit.

No, a cold bath or shower should be avoided. The cold can cause your muscles to contract even more intensely, increasing shivering and potentially causing your temperature to rise further. A lukewarm sponge bath is a safer, more effective option for gently bringing a fever down.

The reason is the same for both children and adults. The child's brain has reset its temperature set-point higher, and their body's shivering is an attempt to raise their body temperature to match that new setting. It is an active immune response, but a high fever in a young child should always be monitored closely.