Escalofríos

Escalofríos, commonly known as chills in English, are a sensation of coldness that can occur with or without a fever. They are often accompanied by shivering, which is involuntary muscle contractions that generate heat. Escalofríos are a common symptom of various conditions, most frequently infections such as the flu, common cold, or more serious bacterial infections.

The body's response of escalating is an attempt to raise its internal temperature. This can be triggered by the immune system releasing chemicals called pyrogens, which signal the hypothalamus in the brain to increase the body's set point for temperature. The shivering that accompanies chills is the muscles rapidly contracting and relaxing to produce heat.

While chills are most often associated with illness, they can also be caused by other factors. Exposure to cold temperatures without adequate protection can lead to chills as the body tries to conserve heat. Certain medications, particularly those used in chemotherapy, can also induce chills as a side effect. Psychological factors, like extreme fear or anxiety, can sometimes manifest as a feeling of coldness and shivering, though this is less common and typically not accompanied by a true fever.

If chills are accompanied by a high fever, severe pain, stiff neck, or difficulty breathing, it is important to seek medical attention as these could indicate a serious underlying condition. Otherwise, for mild chills associated with common colds or flu, rest, hydration, and over-the-counter fever reducers may be sufficient.