What temperature is a fever?
In adults and children, a fever is generally a body temperature of 100.4°F (38°C) or higher. Normal body temperature averages around 98.6°F (37°C) but varies from person to person and across the day, running a bit lower in the early morning and higher in the late afternoon. A healthy range is roughly 97–99°F (36.1–37.2°C).Fever in babies and young children
Children run fevers often, and the number alone isn’t the whole story — how the child looks and acts matters more. Contact a doctor if:- An infant under 3 months has any fever of 100.4°F (38°C) — this is urgent.
- A child is very sleepy or hard to wake, unusually irritable, or limp.
- There are signs of dehydration, trouble breathing, a stiff neck, or a rash that doesn’t fade under pressure.
- A fever is high or persistent, or you’re simply worried — trust your instincts.
Fever in adults
Most adult fevers from common viral illnesses resolve on their own with rest and fluids. Seek care for a fever that is very high, lasts more than a few days, keeps returning, or comes with severe symptoms like difficulty breathing, chest pain, confusion, or a stiff neck.When it’s an emergency
Go to the ER or call 911 for a very high fever that won’t come down (around 104°F/40°C or above), or any fever with confusion, a stiff neck, difficulty breathing, a seizure, a non-fading rash, or signs of severe dehydration.Measuring accurately matters
A fever reading is only as good as your technique and method — see how to take an accurate temperature. SonoHealth offers the ThermoPRO and ThermoMax thermometers for quick home readings; browse them at SonoHealth.com.Related: How to Take an Accurate Temperature