When you’re shivering from a fever, the most helpful thing you can do is use a light blanket for comfort, take a fever reducer, and drink fluids steadily. The shivering feels alarming, but it’s your body’s normal mechanism for generating heat. It will stop on its own once your temperature reaches the new target your brain has temporarily set.
Why Fever Causes Shivering
When you get an infection, your immune system releases signaling molecules that travel to a temperature-control center deep in your brain. This center essentially raises your body’s thermostat, deciding that 101°F or 102°F is the new “normal” for the time being. The problem is that your actual body temperature is still at its usual 98.6°F, so your brain interprets that gap the same way it would interpret standing outside in the cold. It triggers shivering to close the gap.
Shivering is remarkably effective at producing heat. During intense shivering, your body can generate four to five times the amount of heat it produces at rest. That’s why you may feel freezing even though a thermometer confirms you’re running hot. Once your temperature climbs to match the new set point, the shivering stops.
What to Do Right Now
Use a single blanket or light layer if the chills are making you miserable. Research on cooling blankets in hospitalized fever patients found that warmer blanket temperatures provided the same rate of cooling as colder ones but were significantly more comfortable and caused less shivering. The goal is comfort, not heat-trapping. Piling on heavy quilts can push your temperature higher than your body intended and increase your risk of dehydration through excessive sweating.
Take a standard over-the-counter fever reducer. These medications work by lowering the brain’s reset thermostat back toward normal, which addresses the root cause of the shivering. Follow the dosing instructions on the package, and if you’re already taking other medications, check labels carefully for overlapping ingredients.
Skip the cold sponge bath. Tepid sponging has been shown to be significantly less effective than fever-reducing medication. In one study, sponging lowered temperature by only 0.39°C after two hours, while medication brought it down by 1.6°C. The UK’s National Institute of Health and Care Excellence recommends against using tepid sponging for febrile children entirely. Cold water or ice baths are even worse, because they can intensify shivering, which forces your body to produce more heat and works against what you’re trying to accomplish.
Staying Hydrated During a Fever
Fever increases the amount of water your body loses through your skin and breathing. For every degree Celsius above 38°C (100.4°F), your skin loses roughly 10% more water than usual. If you’re also breathing faster, which is common during illness, respiratory water loss can increase by 20 to 50%. That adds up quickly, especially if the fever lasts more than a day.
Water, diluted juice, broth, and oral rehydration solutions all work well. Sip steadily rather than forcing large volumes at once, particularly if you feel nauseous. For children, offer small amounts frequently. If you notice you’re urinating much less than normal or your urine is dark, increase your intake.
When the Shivering Stops and Sweating Starts
Once the fever breaks, either naturally or because medication kicked in, the thermostat in your brain drops back down. Now your actual body temperature is higher than the new set point, so your body does the opposite of shivering: it dilates blood vessels near the skin and triggers sweating to dump heat. You may go from feeling freezing to feeling overheated in a short window.
At this point, swap out damp clothing and bedding. Switch to lighter layers and continue drinking fluids to replace what you’re losing through sweat. This phase is usually a sign that the fever cycle is winding down, at least temporarily.
Rigors vs. Ordinary Chills
Most fever-related shivering is mild to moderate: you feel cold, maybe your teeth chatter, and wrapping up in a blanket helps. Rigors are a more extreme version. They involve violent, uncontrollable shaking that can make an entire bed vibrate. Rigors are the body’s reaction to a severe infection or a large release of bacteria or viruses into the bloodstream. They often accompany very high fevers.
A single brief episode of rigors doesn’t automatically mean something dangerous is happening, but repeated or prolonged rigors deserve medical attention, especially when paired with other warning signs.
Signs That Need Medical Attention
Most fevers with shivering resolve on their own or with basic care. But certain combinations of symptoms can signal a more serious infection. Watch for a rapid heart rate, fast breathing, confusion or difficulty staying alert, very low blood pressure (feeling faint when standing), extreme pain, warm or clammy skin, or producing very little urine. These can be early indicators that an infection is overwhelming the body’s ability to manage it.
For adults, a fever that persists above 103°F despite medication, or any fever lasting more than three days, warrants a call to your healthcare provider.
Febrile Seizures in Children
In young children, rapid temperature spikes can occasionally trigger febrile seizures. These look like uncontrollable shaking or convulsions, muscle stiffening, and sometimes a brief loss of consciousness. They’re different from ordinary shivering because the child typically loses awareness and cannot respond to you.
If your child has a seizure during a fever, note the time it starts. Gently lower them to the floor, away from furniture or hard surfaces. Do not try to hold them down or place anything in their mouth. If the seizure lasts longer than five minutes, call emergency services immediately. All first-time febrile seizures need medical evaluation, even if the child recovers quickly and seems fine afterward. Your provider will confirm it was a febrile seizure rather than something more serious.