A fever is a temporary elevation of the body’s temperature, occurring as a natural response to an underlying illness or infection. When a person feels unwell and their temperature rises, the impulse is often to bundle up under blankets to feel warmer. This reaction can be counterproductive to the body’s attempt to manage the temperature change. Understanding the physiological process behind a fever helps inform decisions about covering up.
Understanding the Fever Cycle and Chills
The body’s temperature control center, the hypothalamus in the brain, acts like an internal thermostat. When the immune system detects a pathogen, it releases signaling molecules called pyrogens into the bloodstream. These pyrogens signal the hypothalamus to raise the body’s temperature set point above the typical 98.6°F (37°C).
Because the set point is raised, the current body temperature is perceived as too cold, even if it is already elevated. To reach the new temperature, the brain triggers heat-generating mechanisms. Peripheral blood vessels constrict to reduce heat loss, and involuntary muscle contractions, known as shivering or chills, rapidly produce heat.
Immediate Guidance: Covering Up Based on the Fever Phase
Guidance on covering up depends entirely on the phase of the fever. During the rising phase, when the person is shivering and experiencing chills, light covering is acceptable for comfort. A single light blanket or thin layer of clothing can help reduce the intensity of muscle contractions, but heavy comforters or excessive layers should be avoided.
Once the fever begins to break, the strategy must change immediately. As the hypothalamus resets the temperature set point back to normal, the body needs to lose accumulated excess heat. The person will feel flushed, warm, and may begin to sweat profusely. Keeping heavy blankets on during this phase traps heat, preventing the necessary cooling process. Immediate removal of thick coverings is required to allow heat to dissipate and sweat to evaporate. Preventing the body from shedding heat can prolong the fever.
Safe and Effective Fever Reduction Methods
Supporting the body’s natural processes with non-pharmaceutical methods is the first line of defense for managing discomfort. Maintaining adequate hydration is extremely important, as the increased body temperature and sweating lead to greater fluid loss. Drinking water, clear broth, or oral electrolyte solutions helps replenish fluids and minerals lost during the fever.
Over-the-counter medications can help lower the temperature and alleviate general body aches associated with the illness. Common medications include acetaminophen and ibuprofen, which work by blocking the production of the temperature-raising pyrogens in the brain. Follow dosage instructions precisely, especially when administering medication to children, and never give aspirin to a child due to the risk of Reye’s syndrome.
External cooling methods are also effective when used correctly, focusing on gradual temperature change to prevent triggering shivering. A lukewarm bath or sponging the skin with tepid water promotes heat loss through evaporation. Use lukewarm water, not cold, because cold water can cause the blood vessels to constrict and trigger shivering, which would paradoxically raise the body’s core temperature.
Warning Signs: When to Call a Doctor
While most fevers resolve on their own, certain signs indicate the need for prompt medical attention. For adults, a temperature reaching or exceeding 104°F (40°C) warrants a call to a health care provider. A fever that persists for more than three to five days without improvement should also be medically evaluated.
In infants younger than three months, any temperature of 100.4°F (38°C) or higher requires an immediate medical assessment. For both adults and children, seek emergency care if the fever is accompanied by severe symptoms. These include a stiff neck, mental confusion, difficulty breathing, or a non-blanching rash.