Fever Reducer: Practical Steps to Treat a Fever Safely

Fever is a common response to infection. It can feel scary, but the goal is comfort, not a specific number on the thermometer. This page explains simple, safe choices for reducing fever, how to dose medicines, and when you should call a doctor.

How to choose and dose a fever reducer

Two drugs do the job most often: acetaminophen (Tylenol) and ibuprofen (Advil, Motrin). For adults, acetaminophen is usually safe up to 3,000–4,000 mg per day depending on product directions; many experts recommend staying under 3,000 mg daily to protect the liver. OTC ibuprofen is usually limited to 1,200 mg per day unless your doctor gives a higher dose.

Children need weight-based dosing. A common acetaminophen dose is 10–15 mg per kg every 4–6 hours, not exceeding the daily limit your pediatrician recommends. For ibuprofen, typical dosing is 5–10 mg per kg every 6–8 hours, with a usual safety cap around 40 mg per kg per day. Always use the measuring device that comes with the medicine and check the package for exact instructions.

A few rules that help avoid mistakes: do not give aspirin to children or teenagers because of the risk of Reye's syndrome; avoid extra-strength doses without medical advice; don’t mix products that both contain acetaminophen (many cold medicines do). If someone has liver disease or drinks heavily, skip acetaminophen unless a doctor approves. If someone has kidney disease, ulcers, or takes blood thinners, be cautious with ibuprofen and talk to a clinician first.

Practical tips and when to seek help

Measure temperature correctly—oral, ear, or temporal thermometers work well when used right. Treat the person, not the number: if they’re drinking fluids, responsive, and resting, a fever can be managed at home. Give fever reducers to improve comfort, help with sleep, and keep the person hydrated.

Call a doctor or get emergency care for infants under 3 months with a rectal temperature of 100.4°F (38°C) or higher. Also seek help if fever is very high (about 104°F / 40°C), lasts more than 72 hours, or if there are worrying signs: difficulty breathing, extreme drowsiness, persistent vomiting, severe headache, stiff neck, rash, or signs of dehydration. If you’re unsure, a quick phone call to your pediatrician or urgent care can clear things up.

Want to alternate acetaminophen and ibuprofen? It’s sometimes done for persistent fever in children, but it can cause dosing errors. If you try it, write down each dose and the time, and check with your pediatrician first. Simple care—rest, cool fluids, and proper dosing—usually keeps most fevers from getting worse.

If you have specific health issues or take regular medicines, ask your doctor which fever reducer is safest for you. Small choices now can prevent big problems later.