What Is a Fever? Causes, Symptoms, and Treatment

Flushed, hot face, but find yourself needing layers of blankets to avoid the chills? This sounds like fever symptoms, but you won’t know until you take your temperature. Often caused by a cold or flu virus, fevers can knock you off your feet and straight into bed. Medicines like NyQuil and DayQuil have acetaminophen, an active ingredient that reduces fever. Find out what causes fever, so you can treat it and feel better.

What is a fever?

Ever notice how when you have a fever you feel hot and sweaty? These symptoms associated with fever occur because a fever is a temporary increase in your body temperature.

A fever is the elevation of body temperature above the ideal temperature of 98.6°F (37° C).1 The U.S. Centers for Disease Control and Prevention (CDC) defines a fever as a temperature at or above 100.4°F (38° C).2

Fevers are extremely common and tend to occur as part of the body’s response to infection as it works to protect itself and fight off viruses like a cold or the flu.3–5

The specific nature and severity of fevers vary depending on a number of factors.5 Fevers can work to combat problematic conditions within the body such as to kill off invading cold and flu viruses. Fevers also need to be monitored to ensure that they do not get high enough to cause damage to your body.4

Read on to learn more about what causes a fever and how to treat it.

What causes a fever?

One of the most common causes of fever is infection, such as infection from a cold or flu virus.6,7 Fever-causing viral infections are often highly contagious and spread from person to person through hand-to-hand transmission or transmission via respiratory droplets in the air.8

People tend to contract cold and flu viruses when the they enter their bodies through the mouth, nose, or eye.6

How long does a fever last?

The duration of fevers varies and usually depends on both the cause of the fever, and if and how treatments are used to lower the body’s temperature. However, even with treatment, fevers will often come back while your body is fighting off a pathogen, after the medication wears off.

In the case of common fever-inducing conditions like colds and flus, fevers are usually last 3-4 days9

What do fever symptoms feel like?

Wondering how to tell if you have a fever? Don’t rely on placing your hand to your forehead—that won’t give you an accurate read to your internal body temperature. Take your temperature with an easy-to-use thermometer. However, there are also certain signs that can help you assess the likelihood that you have a fever.

If you have a fever, you may experience these symptoms:2

  • Feel warm to the touch. Because a fever causes a rise in your body temperature, it may make your skin feel hot and sweaty. Warm skin is common with fevers.
  • Have chills. Another way to tell if you have a fever is if you feel chilled and find yourself shivering, part of your body’s immune response that generates more body heat to help fight the virus.
  • Look sick. A flushed face and glassy eyes often occur with fever and can be used as signs that it may be time to take your temperature.
  • Suffer body aches and pains. Other symptoms that commonly occur with a fever are aches, including headaches, and muscle aches.

How can I treat a fever associated with cold or flu? 

Treating a fever depends on several factors, including how severe it is. Often, as is the case with low-grade fevers, treatment increases comfort and reduces symptoms associated with the fever from a cold or flu.8 Medications like acetaminophen have been shown to reduce fevers.11

Many over-the-counter cold and flu medicines treat multiple symptoms. Make sure to identify what other symptoms you may be experiencing along with fever, if any, so you can get the relief you need.

Liquids and LiquiCaps™

Look for a multi-symptom medicine that fits the symptoms you need relieved. NyQuil SEVERE and DayQuil SEVERE contain maximum symptom-fighting ingredients to relieve your worst cold and flu symptoms, like fever. They also relieve nasal/sinus congestion, sinus pressure, and cough symptoms. It also comes as caplets with a rush of soothing Vicks Vapors.

DayQuil and NyQuil Hot Remedy

You may want to curl up with a medicated hot drink when fever symptoms make you extra chilly. DayQuil or NyQuil Hot Remedy will do the trick. Dissolve the packet into 8 oz. of hot water, stir, and sip while hot. Make sure to drink the entire medicated drink within 10-15 minutes. The soothing Vicks Vapors will comfort you as you sip on the medicated hot drink. Plus, the acetaminophen will help reduce your fever.

Tepid Sponging

With this method, washcloths that have been placed in the water are applied to parts of the patient’s body for roughly five minutes. While there has been some data to suggest that this is an effective measure for breaking a fever, the data are mixed.13There is also evidence to suggest that tepid sponging is no more effective than medications in reducing fever.13

In certain cases, treating a fever at home is insufficient, and it is necessary to talk to a doctor. You should consult your doctor in the following cases:12

  • If your temperature reaches 104°F or higher.
  • If you have fever or cough symptoms that improve, then get worse.
  • If your fever is accompanied by a severe muscle pain, mental confusion, or any other out-of-the ordinary symptoms.

How to Avoid Spreading Fever Symptoms

While fevers cannot always be avoided, maintaining good health can help to prevent a fever. Because colds and flus are a major contributor to the development of fever, taking measures to avoid contracting these viruses is a promising way to avoid a fever. Additionally, because colds and flus are highly contagious and can significantly impact vulnerable populations, taking measures to prevent the spread of these viruses can also help others to avoid fevers and other problems associated with colds and flus.14,15

Here are some basic ways to avoid getting a fever or spreading fever-causing viruses to others:

  • Maintain healthy habits. When you are healthy and your immune system is functioning optimally, you are less likely to get colds and flus that can lead to fevers. For instance, getting plenty of sleep can reduce your chances of getting sick.16
  • Getting a flu shot. Getting a flu shot each year is one way to reduce the chances that you are infected with the flu or that you act as a vector to spread the virus to others.17
  • Washing your hands. Washing your hands with soap and water for 15 to 20 seconds is thought to be sufficient for removing viruses that could infect you or others. 8,18,19 Though not always as effective and soap and water, hand sanitizers can also help to reduce infectious agents on your hands, so using hand sanitizers when it is not possible to wash your hands with soap and water can help prevent viruses that lead to fever.20,21
  • Social distancing. Because we tend to catch viruses from others, staying away from people who are sick and keeping ourselves isolated when we are sick are good ways to reduce the chances of contracting or spreading illnesses that lead to fever.21,22 Even in cases where you are physically around others who are sick, refraining from touching them can help to reduce your chances of getting a virus. Cutting down on hand shaking, for instance, is one effective way to reduce the spread of viruses because viruses are often transmitted by hand-to-hand touching.24
  • Wearing a mask. Wearing a mask creates a physical barrier that can prevent the spread of fever-causing viruses. 8,25 If you are sick, a mask can help prevent you from transmitting a virus to others. Similarly, if those around you are sick, a mask can prevent problematic respiratory droplets in the air from entering your body through your mouth or nose.

While fevers can occur for a variety of reasons, they are often a result of cold and flu viruses. Knowing the symptoms of fever can help you quickly determine when you or a loved one may have a fever and how best to address it. Practicing good habits for preventing the spread of colds and flus can be one of the most effective ways to prevent a fever in yourself and others.

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