Fever in Adults: What's Normal & When to Worry
A fever is the body's natural response to infection. Here's what's considered a fever, how to care for one at home, and the signs that mean it's time to see a doctor.
Fever is generally 38°C (100.4°F) or above
Most settle with rest, fluids, and time
Warning signs mean see a doctor promptly
Same-day walk-in assessment available
A fever — a temporary rise in body temperature — is usually a sign your body is fighting an infection. In most cases it's not dangerous in itself and settles as you recover, but knowing when a fever needs attention takes the worry out of it.
What counts as a fever?
In adults, a temperature at or above about 38°C (100.4°F) is generally considered a fever. How you feel matters alongside the number — most mild fevers can be managed at home with rest, fluids, and time.
Related readingPersistent cough — when it needs checkingOften appears alongside fever — here's when a cough warrants a visit.Caring for a fever at home
Rest, drink plenty of fluids, and dress comfortably. Over-the-counter fever reducers can help you feel more comfortable if appropriate for you. The aim is comfort and hydration while your body does its work.
When to see a doctor
Seek care if a fever is very high, lasts more than a few days, keeps returning, or comes with concerning symptoms — a stiff neck, severe headache, difficulty breathing, persistent vomiting, confusion, a rash that doesn't fade under pressure, or if you simply feel very unwell. People with certain health conditions should seek advice sooner.
How iCollab can help
If you'd like a fever assessed, our walk-in physicians see you by appointment, often the same day, at our Surrey clinics — no family doctor required. For a medical emergency, call 911.
This is general information, not medical advice. If you're seriously unwell, seek urgent care.
Have a concern you'd like looked at?
Book with an iCollab physician, or ask at the walk-in clinic.
A closer look
As you scroll, each part highlights on the diagram. This is general education, not a diagnosis.
Whole body
A fever is a temporary rise in body temperature — usually a sign your body is fighting an infection.
Immune
It's part of the immune response and, in most cases, isn't dangerous in itself and settles as you recover.
Wellbeing
Rest, fluids, and time are the foundation. How unwell you feel matters alongside the number.
Overall health
Certain warning signs — or being at higher risk — mean a fever should be assessed promptly.
Fever in Adults: What's Normal & When to Worry — FAQ
What temperature is a fever in adults?+
When should I worry about a fever?+
Can I be seen the same day?+
When is it an emergency?+
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