When to Worry About Chills With Influenza

Most people with influenza notice chills, sometimes before or alongside a fever. Shivering is the body's way of producing heat while it adjusts its internal temperature. You may feel cold even when your skin is warm. Chills can come in waves and may ease as the fever settles.

Chills alone do not show how serious an illness is. Pay attention to the overall pattern: breathing, alertness, hydration, chest symptoms, and whether the person is improving or becoming more unwell. Infants, older adults, pregnant people, and anyone with a long-term condition may need medical advice sooner because influenza can place extra strain on the body.

Rest, drink frequent small amounts of water or an oral rehydration drink, and use light layers or a blanket for comfort. Avoid heavy bundling if you are feverish. Check that you are passing urine and can keep fluids down. Follow the label or a clinician's instructions for any fever or pain medicine, and check before giving medicines to a child or combining products.

Stay home while unwell and reduce close contact with others, particularly people at higher risk of complications. Contact a clinician promptly if symptoms are worsening, if fever returns after improving, or if you cannot maintain fluids. Early advice may matter for people at higher risk, because some influenza treatments work best when started soon after symptoms begin.

Call emergency services for severe breathing difficulty, persistent chest pain or pressure, new confusion, a seizure, fainting, blue or grey lips or face, or a person who is difficult to wake. For a child, urgent assessment is also needed if they are not drinking, have very few wet nappies or trips to the toilet, or are unusually floppy or unresponsive.

Arrange same-day medical advice for dehydration, repeated vomiting, worsening fever or chills, marked weakness, or symptoms that improve and then become worse. Seek advice early if you are pregnant, immunocompromised, have heart or lung disease, or are caring for a very young child or older adult.

Ask whether your symptoms fit influenza or need another assessment, which medicines are suitable with your health conditions, and what signs should prompt an urgent review. Tell the clinician when the chills began, whether you have measured a fever, how much you are drinking, and whether breathing or alertness has changed.