Fever in Japan – Guide for Tourists
A fever during travel is unsettling, especially when you do not speak the local language or know which medicine is safe. This guide covers Japan’s temperature standards, what to buy at a Japanese pharmacy, when to see a doctor, and what to expect at a clinic visit.
Understanding Your Fever
Japan defines fever slightly differently from many other countries, and Japanese thermometers display only Celsius. Knowing the local standards may help you decide whether to rest at the hotel or seek medical care.
Japanese Temperature Standards
- Below 37.0°C (98.6°F): generally considered normal body temperature.
- 37.0–37.4°C (98.6–99.3°F): elevated, but not officially fever in Japan.
- 37.5°C (99.5°F) and above: classified as fever in Japan. Most workplaces and schools generally require staying home.
- 38.0°C (100.4°F) and above: medical consultation is generally recommended, especially with other symptoms.
- 39.0°C (102.2°F) and above: high fever — seeing a doctor the same day is generally advised.
- 40.0°C (104.0°F) and above: potentially dangerous — treat as a possible emergency.
Buying a Thermometer
Digital thermometers (taionkei, 体温計) are sold at any pharmacy or drugstore for around ¥1,000–¥3,000. They display Celsius only. Most are oral or under-arm; ear and forehead infrared models are also widely available. If you usually think in Fahrenheit, saving a quick conversion note on your phone using the table above may help.
Common Causes of Fever for Tourists
Several common conditions can cause fever during a trip to Japan. Identifying the likely cause may help you decide whether self-care is appropriate or whether seeing a doctor would be wise.
- Flu and the common cold. Seasonal influenza is widespread in Japan from December through March, with a smaller secondary peak in late summer. Symptoms may include high fever, body aches, cough, and fatigue. A simple cold usually causes only mild fever (under 38°C) along with a runny nose and sore throat.
- COVID-19. Still circulating in Japan year-round. Antigen test kits (kougen kensa kitto) are sold at most large pharmacies for around ¥1,000–¥2,500. If you test positive, isolating as much as possible and contacting your accommodation for guidance is generally advised.
- Heat exhaustion. Japanese summers (June–September) are hot and very humid. Body temperature can climb above 38°C with heavy sweating, dizziness, headache, and nausea. Move to a cool place, hydrate, and consider seeking care if symptoms worsen.
- Food-related illness. Bacterial food poisoning often causes fever combined with vomiting, diarrhea, or abdominal cramps within hours of a suspect meal. See our stomach pain guide if these symptoms dominate.
- Travel fatigue and jet lag. Disrupted sleep and long sightseeing days may weaken your immune system. A mild fever during the first few days of a trip may simply mean your body is overworked — rest and fluids often resolve it within 24 hours.
What to Do First
For a mild fever (37.5–38.5°C / 99.5–101.3°F) without alarming symptoms, the following steps are usually enough.
- Rest. Cancel sightseeing for the day and rest at your accommodation. Sleep is often one of the most effective approaches for most viral fevers.
- Hydrate. Drink water, tea, or oral rehydration drinks. In Japan, Pocari Sweat and OS-1 are among the most widely available electrolyte drinks — both are sold at convenience stores and pharmacies.
- Take an over-the-counter fever reducer. Walk into any pharmacy and say “Netsu-samashi o kudasai” (Please give me a fever reducer). See the next section for what to ask for and how to choose.
- Measure your temperature regularly. Every 4–6 hours, and especially before bed and on waking. Keeping a short log on your phone may help if you later see a doctor.
- Watch for warning signs. If your fever reaches 38.5°C (101.3°F) and stays there, or if you develop severe headache, rash, neck stiffness, or difficulty breathing, consider seeing a doctor without delay.
Over-the-Counter Fever Medicine in Japan
Japanese pharmacies stock a wide range of fever reducers (kainetsu-zai) and pain relievers (chintsu-zai). Below are the general categories — asking the pharmacist for what fits your situation may be more reliable than picking by brand.
- Acetaminophen (paracetamol). One of the most commonly recommended options for adults and children in Japan. Generally gentle on the stomach and often considered first-line for travelers.
- Ibuprofen. Often used for fever combined with body aches. Avoid on an empty stomach and skip if you have stomach ulcers, asthma, or kidney problems.
- Combination cold-and-flu medicines (kaze-gusuri). Contain a fever reducer plus cough suppressant and decongestant. May be useful if your fever comes with cold symptoms, but avoid stacking with another fever reducer at the same time.
How to Ask at the Pharmacy
- “Netsu ga arimasu” — I have a fever.
- “Netsu-samashi o kudasai” — Please give me a fever reducer.
- “Kodomo-yo desu” — It is for a child.
- “Eigo no setsumeisho wa arimasu ka?” — Do you have an English instruction sheet?
Important Cautions
- Children and adults need different products. Japanese pediatric formulations are dosed by weight; tell the pharmacist the child’s age and weight. Acetaminophen is generally preferred for children.
- Avoid aspirin in children and teens with fever due to the risk of Reye’s syndrome.
- Tell the pharmacist about other medications you take — especially blood thinners, blood pressure medication, antidepressants, or anything for a chronic condition. Drug interactions can occur even with over-the-counter products.
- If symptoms are severe or do not improve in 24–48 hours, please consider seeing a doctor instead of continuing to self-treat.
Finding a Doctor
For a fever that does not respond to rest and over-the-counter medicine, an internal medicine (naika) clinic is generally a good first stop. If respiratory symptoms dominate, a clinic that handles influenza and COVID-19 testing may be ideal.
In Major Cities
Our city guides list clinics that explicitly welcome international visitors:
In Regional and Rural Areas
Outside major cities, the front desk of your hotel or ryokan can usually call a nearby clinic on your behalf, explain your symptoms in Japanese, and direct you to the right address. Many small towns have only one general clinic, which is often the right place to start.
Evenings, Weekends, and Holidays
Most Japanese clinics close by 18:00 and on Sundays. For after-hours care, ask your hotel about the local night clinic (yakan shinryojo) or call #7119 in supported prefectures (Tokyo, Osaka, and others) for triage advice. For a true emergency, call 119 — the ambulance is free.
Online Consultation as an Alternative
If you would rather not leave your hotel, online doctor consultations are increasingly available in Japan and may suit non-urgent fever. A licensed Japanese physician can assess your condition by video, recommend over-the-counter options, and refer you to a clinic if in-person care is needed.
What to Expect at a Japanese Clinic
Japanese clinic visits are usually quick and efficient. Knowing the flow may reduce stress on a day when you are already unwell.
- Reception. Bring your passport and travel insurance documentation. The front desk hands you a medical questionnaire (monshinhyo). Most regional clinics have it in Japanese only — a translation app on your phone (Google Translate, DeepL) usually handles this in a minute.
- Testing if respiratory symptoms are present. Influenza is confirmed by a rapid swab test, typically with results in 10–15 minutes. COVID-19 is usually checked by antigen test (15 minutes) or PCR (results in hours to a day, depending on the clinic).
- Examination. The doctor checks temperature, listens to your chest, looks at your throat, and asks about onset, recent travel, and existing conditions. Japanese consultations are usually short (5–15 minutes) but thorough.
- Prescription. The clinic itself usually does not dispense most medicines. You receive a paper prescription (shohosen) to take to a nearby dispensing pharmacy (chozai yakkyoku), often within walking distance.
- Payment. Due on the day, at the clinic reception. Cash is generally accepted; many clinics also take credit cards, but smaller facilities may be cash-only — carrying enough yen may be wise.
Insurance & Cost
Without Japanese national health insurance, foreign visitors typically pay full out-of-pocket prices. Travel insurance may significantly reduce or eliminate this cost.
Approximate Costs Without Insurance
- Initial consultation: ¥5,000 – ¥10,000
- Influenza rapid test: ¥2,000 – ¥4,000
- COVID-19 antigen test (clinic): ¥3,000 – ¥6,000
- Prescription medication (3–5 days): ¥1,000 – ¥3,000
Using Travel Insurance
Most travelers pay the clinic in full and submit receipts to their insurer for reimbursement after returning home. Some clinics that frequently see international patients may arrange direct (cashless) billing — calling your insurer’s 24-hour hotline before the visit may help confirm.
Documents to Request
It is generally wise to ask for an itemized receipt (ryoshusho) and, if your insurer requires it, an English-language medical certificate (shindansho). Some clinics charge an additional fee (typically ¥3,000 – ¥5,000) for an English diagnosis letter, but it may be essential for many insurance claims.
When Fever Becomes an Emergency
Most fevers do not require emergency care. The following situations are exceptions — call 119 for an ambulance or go straight to a hospital emergency department.
- Fever of 40°C (104°F) or higher. Especially if it does not come down with fever reducers and rest.
- Confusion, drowsiness, or difficulty waking. A change in mental state with fever may signal severe infection or sepsis.
- Severe headache with neck stiffness. May indicate meningitis — do not wait.
- High fever with rash, particularly a rash that does not fade when you press a glass against it.
- Difficulty breathing or chest pain alongside fever.
- Seizure with fever in a child (febrile seizure). Call 119, place the child safely on their side, and do not put anything in their mouth.
For more on emergency procedures, see our Medical Emergency in Japan guide.
Prevention Tips
A few simple habits may significantly reduce the chance of getting sick during your trip.
- Wash your hands often, especially before eating and after using public transport. Many Japanese restaurants and toilets provide soap and warm water.
- Wear a mask in crowded indoor spaces during flu season. Masks remain socially common in Japan and are sold at every convenience store.
- Stay hydrated and out of the midday sun in summer. Heat exhaustion and heatstroke can be real risks during Japanese July and August. Carry a water bottle and consider an oral rehydration drink on hot days.
- Sleep enough. Long sightseeing days plus jet lag may suppress immunity. Try to keep at least one early night per few days.
- Get a flu shot before traveling in winter. Especially if you will be in crowded transit, theme parks, or with children. Flu vaccine is also available at some Japanese clinics for around ¥3,000–¥5,000 if you arrive unvaccinated.
Frequently Asked Questions
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