First, age decides everything: any fever of 100.4F (38C) or higher in a baby under 3 months means call the pediatrician or go in now. In older kids, fever itself is rarely dangerous - treat the child's comfort, watch how they act, and know the warning signs.
By age: under 3 months - 100.4F+ is an automatic same-day evaluation, no waiting, no telehealth. 3 to 36 months - fever with a happy, drinking, playing child can be watched at home; fever lasting 3+ days or a miserable child earns a call. Over 3 - behavior over numbers: a kid who plays between Motrin doses is usually fine at home. Comfort care: acetaminophen or ibuprofen dosed by weight (not age - check the label or ask the pharmacist; ibuprofen only over 6 months), fluids in any form they will take, light clothing - no bundling, no alcohol rubs, no aspirin ever (Reye's syndrome). The goal of medicine is a comfortable child, not a normal number. Get seen urgently at any age for: trouble breathing, a rash that does not blanch when pressed, stiff neck, severe headache, persistent vomiting, signs of dehydration (no wet diaper or urination in 8+ hours, no tears), a seizure, or unusual lethargy - hard to wake, not just sleepy. Emergencies skip this list: chest pain, trouble breathing, stroke signs, severe bleeding, or thoughts of self-harm mean call 911, or 988 for a mental health crisis in the US.
What to do
Common questions
What fever temperature is dangerous for a child?
The number matters less than folklore says - fevers under 104F do not damage the brain, and the body's thermostat keeps illness fevers below dangerous levels. What matters: age (under 3 months, 100.4F is the hard line), how the child acts (a playful 103F beats a listless 101F), and duration (3+ days earns a call). Fever phobia leads to ER trips a watching eye would have spared - trust behavior over the thermometer.
Should I alternate acetaminophen and ibuprofen?
You can, but you probably should not - alternating schedules are easy to mess up and double-dosing is the real risk. One medication, dosed correctly by weight, handles most fevers. If the child's comfort breaks through before the next dose is due, that is the situation alternating was invented for - write down every dose and time if you do it. Ibuprofen only over 6 months, and avoid it in a dehydrated child.
What is a febrile seizure and what do I do?
A seizure triggered by fever in kids 6 months to 5 years - terrifying to watch, usually harmless. During it: lay the child on their side on a safe surface, time it, put nothing in the mouth, and do not restrain. Call 911 if it lasts over 5 minutes, is the first one, or the child does not recover normally afterward. Most stop within minutes and need a same-day check to find the fever's source; they do not cause epilepsy or brain damage.
When can my child go back to school or daycare after a fever?
The standard rule: fever-free for 24 hours without fever medication. That is not just etiquette - a medicated-normal temperature still carries the infection. The same 24-hour rule applies after vomiting or diarrhea stops. Emergencies skip this list: chest pain, trouble breathing, stroke signs, severe bleeding, or thoughts of self-harm mean call 911, or 988 for a mental health crisis in the US.