Is a fever contagious?
Last updated September 3, 2026.
No - a fever is a symptom, not an illness: your immune system raising the temperature because germs thrive best at normal body temperature. What can be contagious is the infection underneath - flu, strep, or a stomach virus - so the household plans around the cause, not the number. Fever with stiff neck, confusion, trouble breathing, a non-blanching rash, or any fever in an infant under 3 months is urgent regardless of cause.
What to do
- Ask what is causing it. Contagiousness follows the illness, not the temperature.
- Apply the illness playbook. Fever plus cough, sore throat, vomiting, or diarrhea: use that infection's precautions.
- Know the red lines. Stiff neck, confusion, breathing trouble, or non-blanching rash: urgent care.
- Treat infant fevers as their own category. Any fever under 3 months old gets a same-day call.
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