Fever in adults: normal temperature, how to reduce a fever, and when to get help

A fever (lagnat) means your body temperature is higher than usual. It is usually a sign that your body is fighting an infection, and most fevers get better on their own.

Normal body temperature is about 37°C, but it differs from person to person and changes during the day. It is usually highest in the evening. Exercise, a meal, heavy clothes, a hot room and humid weather can push it up a little.

As a simple guide for adults:

• Up to about 37.2°C (mouth): normal for most people.
• Above about 37.2°C to 37.5°C: possibly a mild fever, depending on the time of day.
• 38°C or higher: a fever, the level most health services use.
• 39.4°C or higher that stays up or keeps rising: a high fever that needs a doctor today.

If you feel hot and then cold, are shivering (nanginginig) or sweating, you may have a fever even when the thermometer shows less than 38°C.

A digital thermometer from the botika is the easiest choice. Wait a while after exercise or a meal, which can raise your temperature a little.

1. Clean the tip with soap and cold water.
2. Put it under your tongue and close your lips, or put it in your armpit (kili-kili) with your arm pressed to your side.
3. Wait for the beep, then read the number.

Armpit readings are usually a little lower than mouth readings, so use the same place each time. Avoid glass thermometers, which can be dangerous, and forehead strips, which are not accurate. Writing down each reading and the time helps the doctor later.

Almost any infection can cause a fever. Common ones are:

• colds and flu (trangkaso), sore throat and sinus infections (see our flu symptoms guide)
• chest infections such as pneumonia (pulmonya), and tuberculosis (TB)
• urinary tract infections, often with burning when you pee (see our UTI guide)
• stomach and gut infections, with diarrhea or vomiting
• skin infections, such as an infected wound
• in the Philippines, dengue, leptospirosis and typhoid fever (see Fever for 2 days or more)

A mild fever for 1 or 2 days after some vaccines is common. Some medicines, long-term illnesses such as lupus, and some cancers can also cause fevers. A fever that keeps coming back for days or weeks without a clear reason needs a check-up.

In the Philippines, a fever that has lasted 2 days or more is a reason to get checked, especially in the rainy season, because these illnesses start the same way as a simple flu.

Dengue. PhilHealth's dengue care standards describe a fever of 38°C or higher for 2 to 7 days, with at least two of these: headache, body or joint pain, pain behind the eyes, rash, vomiting or poor appetite. A blood test (CBC with platelet count) helps the doctor. Watch closely as the fever goes down: feeling worse then is a warning sign, not recovery, and means go to the hospital. See our dengue guide.

Leptospirosis (lepto). PhilHealth's lepto guidance tells doctors to think of it when a fever has lasted at least 2 days in someone who waded in flood water, lives in a flooded area, or touched animal urine. Other signs include muscle pain (often in the calves), chills, red eyes, yellow skin or eyes, and peeing less. Severe lepto can harm the kidneys and lungs, so get checked early. If you waded in a flood and have no fever yet, ask your health center whether you need preventive medicine. See our leptospirosis guide.

Typhoid fever spreads through unsafe food or water. The fever often climbs slowly over several days, with headache, tiredness, stomach pain and constipation or diarrhea. It needs blood tests and antibiotics from a doctor.

Tell the doctor if you waded in floods or what you ate and drank in the past few weeks.

If the fever is mild and you have no warning signs, rest and fluids are often enough. The aim is to feel more comfortable, not to reach a perfect number.

• Rest, and stay home until the fever is gone so you don't spread the infection.
• Drink plenty of fluids: water is best, and soup (sabaw) counts. Drink enough that your pee is light yellow and clear.
• Use oral rehydration solution (ORS, oresol) if you are vomiting or have diarrhea. For people with dengue, PhilHealth's care standards advise ORS rather than sports drinks.
• Wear light clothes and use one thin blanket. A fan helps if the room is hot or stuffy.
• Don't bundle up, even with chills. Thick blankets trap heat.
• Try a lukewarm sponge bath (punas) on the forehead, armpits, arms and legs. It works best after a fever medicine.
• Skip cold baths, ice and alcohol rubs. They can make you shiver, which raises your inner temperature.
• Eat what you can, such as lugaw, but don't force yourself.

If the fever is not getting better, is getting worse, or a warning sign appears, get checked. Unsure? Ask our free AI symptoms guide any time.

You don't always need a fever medicine. Take one if the fever makes you uncomfortable, stops you sleeping, or comes with body pain.

Paracetamol is usually the first choice for adults, including in pregnancy and breastfeeding.

• Take it exactly as the label says. Too much can badly damage the liver.
• Check your other medicines. Many cold, flu and pain mixes already contain paracetamol (also called acetaminophen), so taking two can mean too much.
• Ask first if you have liver or kidney disease, or drink alcohol every day or heavily.
• See a doctor if you need it for more than 3 days.
• Took more than the label says? Get medical advice right away, even if you feel fine.

Ibuprofen and aspirin also lower fever. They are NSAIDs, like mefenamic acid, which many homes keep for pain such as period cramps. NSAIDs have more side effects than paracetamol, such as stomach ulcers and bleeding. Ask first if you are pregnant or have asthma, chickenpox, a stomach ulcer, or heart, liver or kidney disease. Avoid them if you might have dengue, because they raise the risk of bleeding. Since an early fever in the Philippines may be dengue, paracetamol is the safer pick unless a doctor says otherwise. Never give aspirin to a child unless a doctor says so.

Antibiotics are not fever medicines. They treat some infections caused by bacteria, but they don't work on viruses such as colds and flu, and there is no specific medicine for dengue. Take them only when a doctor prescribes them. Using them when they aren't needed helps germs become resistant.

Families pass on many ideas about fever. Here is what medical sources say.

• "Bawal maligo kapag may lagnat" (no bathing with a fever). A lukewarm bath or sponge bath can help you feel cooler. Avoid very cold water and dry off well.
• "Pagpawisan" (sweat it out under blankets). Bundling up traps heat. Light clothes are better.
• Alcohol or ice rubs. Not advised, because shivering pushes the temperature up.
• "A high fever damages the brain." Fevers from infection rarely get that high. Brain damage from fever generally does not happen below about 42°C. How you feel and any warning signs matter more. Heatstroke is different and is an emergency (see Fever or too much heat?).
• Binat (falling sick again too soon). Rest does help recovery. But a fever that goes away and comes back should be checked.

Herbal drinks may comfort you, but they should never delay a check-up.

In the hot months (tag-init), a high temperature can come from the heat. Heat exhaustion brings tiredness, dizziness, headache, heavy sweating, cramps and strong thirst. Move the person to a cool place, remove extra clothing, give water or ORS, and cool the skin with water and a fan. They should feel better within 30 minutes.

Heatstroke is an emergency: hot skin that is not sweating, fast breathing, confusion, a seizure or passing out. Get help now and keep cooling them while you wait.

Infections can turn serious faster in some people. Get a fever checked early if you are:

• an older adult (older people may not get a high fever even with a serious infection)
• pregnant, or gave birth or had a miscarriage in the past 6 weeks
• living with diabetes, heart disease, COPD or another long-term lung or kidney problem
• living with a weak immune system, for example from cancer treatment, long-term steroids or HIV
• caring for a wound, burn or skin infection, or using a urinary catheter
• just back from a trip abroad

Sepsis is a dangerous reaction to an infection that can get worse within hours. In adults, signs include confusion or slurred speech, uncontrollable shivering, muscle pain, trouble breathing, pale, grey or blotchy skin, and peeing very little. The temperature can be high or unusually low. If you feel something is seriously wrong, trust that and go to the emergency room. Ask someone to take you instead of driving.

This guide is for teens and adults. For children, see our guide to fever in babies and children.

• Barangay health station, rural health unit (RHU) or city health center. A good first stop for a fever of 2 days, a fever after a flood, or a fever with other symptoms. Find one near you.
• PhilHealth YAKAP clinic. As of July 2025, registered members get free check-ups and the lab tests their YAKAP doctor recommends. Prescribed medicines are free at accredited GAMOT pharmacies up to ₱20,000 a year per person. A private YAKAP clinic may charge up to ₱900 a year. In January 2026, PhilHealth said 21 essential medicines, including paracetamol and ORS, stay available at YAKAP clinics. See our PhilHealth YAKAP guide.
• Leptospirosis. PhilHealth covers mild lepto through YAKAP, GAMOT and its outpatient emergency care package. Since July 15, 2026, its hospital package for moderate to severe lepto is ₱63,000 (higher if dialysis or breathing support is needed), and accredited hospitals may not charge extra for covered care in a ward bed. For dengue costs, see our dengue guide.

Bring your temperature notes, the medicines you took and your PhilHealth number. In an emergency, go to the nearest hospital (find a hospital). You can also book a call with a nurse.