Heart palpitations with fever and chills: what to know

Fever commonly makes the heart beat faster as the body responds to illness. Chills can occur while temperature is rising, and sweating or poor intake may cause dehydration. Pain, anxiety, stimulant medicines, and some infections can add to the sensation. Palpitations should be judged alongside breathing, alertness, hydration, and the course of the illness.

A fast heartbeat can be a normal response to raised temperature, but a very irregular rhythm, worsening weakness, or breathlessness needs attention. Dehydration is more likely when there is vomiting, diarrhoea, heavy sweating, or difficulty drinking. Anaemia, thyroid disease, and atrial fibrillation can also cause palpitations, although fever may be the immediate trigger. The heartbeat alone cannot show whether an infection is mild or serious.

Rest, take fluids in small regular amounts if you can, and monitor your temperature and symptoms. Follow the label or clinician's instructions for any fever medicine and check that cold remedies do not contain stimulants that worsen racing. Avoid strenuous activity, caffeine, and alcohol. Contact a clinician if fever persists, fluid intake is poor, or palpitations keep returning after you rest.

Seek emergency help for severe breathlessness, chest pain, fainting, new confusion, blue lips, or a rapidly worsening condition. Get urgent assessment for a sustained very fast or irregular heartbeat, inability to keep fluids down, or signs of severe dehydration such as very little urine and marked weakness.

Tell the clinician when the fever and palpitations began, how high your temperature has been, recent fluid loss, medicines taken, and any cough, urinary symptoms, rash, or localised pain. Ask whether you need an examination, electrocardiogram, or tests for infection and anaemia.