PanicStation.org
UK USA
us Health & medical scares

What to do if…
you have a fever and your heart rate feels unusually fast at rest

Produced and maintained by PanicStation.org Published: Last reviewed: Editorial policy USA guide

Short answer

If your heart is racing at rest with fever and you feel very sick, treat it as urgent: call 911 for severe symptoms such as trouble breathing, chest pain, confusion, fainting, seizure, or feeling like you might collapse. If you are stable but the fast heartbeat still feels unusual, get same-day medical triage from urgent care, your clinic, a nurse line, or an emergency department.

Do not do these things

  • Don’t try to “sweat it out” with exercise, hot showers, saunas, or heavy blankets.
  • Don’t take extra doses of acetaminophen or ibuprofen to chase a lower temperature.
  • Don’t accidentally double-dose acetaminophen; it may also be listed as APAP and can be in cold, flu, and pain products.
  • Don’t ignore a fast pulse just because the fever is not very high; the combination of symptoms matters.
  • Don’t drive yourself if you are faint, confused, extremely weak, short of breath, or having chest pain.

What to do now

  1. Stop and take quick readings.

    • Sit still for a minute if you can.
    • Take your temperature.
    • Count your resting pulse for 60 seconds.
    • Write down the time, temperature, pulse, and any medicines you took.

  2. Check for emergency symptoms. Call 911 now if you have any of these:

    • Chest pain or chest pressure.
    • Severe trouble breathing.
    • New confusion, seizure, or trouble staying awake.
    • Fainting, near-fainting, or feeling like you might collapse.
    • Blue or gray lips, face, or skin.
    • Severe weakness, clammy skin, or rapidly worsening symptoms.

  3. Escalate quickly if infection feels severe. Go to an emergency department now, or call 911 if you cannot get there safely, if you have fever with a racing or weak pulse at rest and you feel severely ill, are rapidly worsening, are peeing very little, have severe shaking chills, or have more than one emergency warning sign. If this started with a suspected infection, such as a respiratory, urinary, skin, wound, dental, or abdominal infection, tell triage: “I have fever, a fast heart rate at rest, and I am worried about sepsis.”

  4. Get same-day triage if you are stable but concerned. If you are alert, breathing normally, not faint, and not having chest pain, contact urgent care, your clinic’s nurse line, a telehealth service, or your health plan’s nurse line today. Say: “I have a fever and an unusually fast heart rate at rest. My temperature is __ and my pulse is __.”

  5. Reduce strain while arranging care.

    • Sit upright, or lie down if you feel dizzy.
    • Keep the room comfortably cool.
    • Sip fluids steadily if you can swallow safely.
    • If you cannot keep fluids down for hours, are peeing very little, or feel worse after trying fluids, escalate to urgent care or an emergency department.
    • If you can take them safely, use acetaminophen or ibuprofen only as directed on the label; avoid ibuprofen if a clinician has told you not to take it.

  6. Keep the triage summary simple. Use one sentence: “I have a fever and a very fast heart rate at rest; my readings are temperature __ and pulse __, and I’m also having __.”

What can wait

  • You do not need to figure out the exact cause before seeking care.
  • You do not need to keep checking your pulse every few minutes once you have written down the first reading.
  • Work, travel, exercise, chores, and non-urgent plans can wait until you have been triaged and are stable.
  • You do not need to decide now whether this is anxiety, dehydration, flu, COVID, or another infection.

Important reassurance

A fast heart rate can happen with fever, pain, dehydration, anxiety, and infection. You are not overreacting by noticing that it feels unusual at rest; getting triage is a reasonable way to make the next decision safer.

Scope note

These are first steps only. Diagnosis, testing, and treatment depend on your symptoms, exam findings, medical history, and clinician assessment.

Important note

This is general information, not medical advice, diagnosis, treatment, or a substitute for professional medical care. If you are worsening or unsure which level of care is safe, choose urgent evaluation.

Additional Resources

Closely connected guides that may be useful during the same situation or its immediate aftermath.

About this guide

This guide was produced and is maintained by PanicStation.org using its published editorial process. Official and specialist sources are checked where relevant, and AI-assisted tools may be used for drafting, organisation, and consistency checks. The site operator remains responsible for publication, revision, and removal decisions.

Support us