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Dr. Chrysoula I. Liakou MD, PhD
- Treated online: Yes, usually, for adults: a fever is assessed by video and its cause treated where a prescription is right; a fever with a non-fading rash, stiff neck, severe breathlessness or confusion needs in-person care now.
- What it is: a body temperature of 38°C (100.4°F) or above; normal is around 36.5 to 37.2°C and shifts through the day, and the number matters less than how the person looks and behaves.
- How long: most fevers with an obvious cold or flu settle within 3 to 5 days; a fever lasting longer, returning after settling, or with no clear source needs assessment.
- Lowering it: paracetamol or ibuprofen ease the aches and discomfort of a fever but do not treat the infection or shorten the illness; use them for comfort, not to chase the number.
- Babies: a temperature of 38°C or higher in a baby under 3 months always needs urgent in-person assessment, never a video call.
- Emergency: call 112 for a fever with a rash that does not fade under a glass, a stiff neck with dislike of bright light, severe breathlessness, a fit, or someone who is very drowsy, confused or hard to wake.
Some fevers need in-person care now, not a video call. A baby under 3 months with a temperature of 38°C or higher, a rash that does not fade when pressed with a glass, a stiff neck with dislike of bright light, a fever with severe breathlessness, or someone who is very drowsy, confused or hard to wake all need urgent assessment. If a rash does not fade under a glass, or you cannot rouse the person, call 112.
Can an online doctor help with a fever?
Often, yes. A fever is a sign, not a diagnosis, so a video consultation focuses on finding and treating the cause: a licensed doctor takes a full history, checks for warning signs, and prescribes when a treatable infection is found. A baby under 3 months with any fever, or anyone with signs of serious illness, needs in-person care instead.
Fever is one of the body's normal responses to infection, which is why the number on the thermometer matters far less than how the person looks and behaves. A video consultation is well suited to that judgement: the doctor can see how unwell you are, hear how your breathing sounds, and work through the questions that separate a self-limiting virus from something that needs tests or a prescription.
Listen: Fever Treatment Online
The audio version of this topic from the Mobi Doctor podcast. Open the episode.
How an online consultation helps with a fever
- Cause over number: the doctor looks for the source of the fever (throat, chest, urine, ear, sinuses, skin) rather than fixating on the exact temperature, because the focus of the infection is what decides the treatment.
- A clear red-flag check: you are screened for the specific warning signs that make a fever dangerous, from a non-blanching rash to breathlessness or confusion, so you know exactly what would mean escalating to in-person care.
- Prescriptions after a proper consultation: if the assessment points to a bacterial infection such as a urine infection or tonsillitis, treatment can be prescribed, with the prescription usable at a pharmacy near you. Most fevers are viral and need no antibiotic at all.
- Honest advice on lowering a fever: the doctor explains what paracetamol and ibuprofen actually do (ease discomfort, not cure the infection) and gives a written safety net for what should improve, and by when.
What counts as a fever?
A fever is usually defined as a body temperature of 38°C (100.4°F) or above.[1] Normal body temperature sits around 36.5°C to 37.2°C and varies through the day, with the reading also depending on where and how you measure it. Because of that, a single figure means little on its own. What the doctor weighs is the whole picture: how high, how long, how you feel, and what other symptoms sit alongside it.
Temperature can be measured under the arm, in the ear or on the forehead, and each method reads slightly differently. In small children, an electronic thermometer under the arm is a reliable everyday choice.[4] Whatever the method, treat the number as one clue among several rather than the verdict, because a person can be seriously unwell with only a modest fever, and quite well with a high one.
What causes a fever?
The great majority of fevers are caused by common infections the immune system clears without specific treatment: colds, influenza, sore throats, chest and urine infections, and other common viral illnesses. The raised temperature is the immune system working, not the enemy itself. Less commonly, a fever comes from a bacterial infection that does need antibiotics, from inflammatory conditions, from certain medicines, or after travel to regions where illnesses such as malaria circulate, which is why the doctor always asks where you have recently been.[5]
A fever that follows an obvious cold and settles within a few days rarely needs investigation. A fever that arrives with no clear source, keeps climbing, returns after you had improved, or drags on beyond about five days deserves a proper look, because those patterns are more likely to have a cause that treatment can change. Prolonged tiredness with fever and very swollen glands in a teenager or young adult can point to glandular fever, which is assessed differently.
Fever in adults: when it needs assessment
Most adult fevers accompany an infection you can already name, such as a heavy cold or the flu, and they settle with rest, fluids and time. Book a consultation if your fever lasts more than three to five days, keeps returning, climbs despite paracetamol or ibuprofen, or comes with symptoms that point to a treatable focus: burning or frequent urination, a productive cough with breathlessness, severe one-sided throat pain, or a spreading area of hot red skin. These are the fevers where finding the source changes what happens next.
Certain adults are assessed sooner and more carefully: people who are pregnant, over 65, or living with diabetes, a weakened immune system, or heart, lung, kidney or liver disease. A fever with severe breathlessness, chest pain, confusion, a fast heartbeat, cold or mottled skin, or very little urine can be a sign of sepsis, the body's overwhelming response to infection, and is a medical emergency at any age.[2] Sepsis is treatable, and treated fastest when it is recognised early, so those signs mean urgent in-person care rather than a video call.
Fever in children
Fever is one of the most common reasons children see a doctor, and most childhood fevers are due to viral infections that pass in a few days. The reassuring signs are a child who, once the temperature eases, will smile or play, take fluids, and settle. The concerning signs are about how the child looks and behaves, not the height of the fever, and some scenarios are emergencies regardless of the number.
Under 3 months: always urgent
A temperature of 38°C or above in a baby under 3 months old is treated as a medical emergency and needs same-day, in-person assessment, because serious infection is harder to spot and moves faster in very young babies.[1] This is not a situation for online care: contact your out-of-hours service or go to an emergency department the same day. Between 3 and 6 months a fever also warrants a lower threshold for review.
The meningitis and sepsis signs every parent should know
Call 112 or go straight to emergency care if a feverish child develops a rash that does not fade when you press a clear glass firmly against it (the glass or tumbler test), an unusually stiff neck, a strong dislike of bright light, an abnormally high-pitched or continuous cry, a bulging soft spot on a baby's head, cold hands and feet with a hot body, or becomes floppy, unresponsive or very hard to wake.[3] A non-blanching rash is a late sign, so never wait for it: if a child is deteriorating, act on the overall picture. Fast or laboured breathing, blue lips, a fit (febrile convulsion) that lasts more than five minutes, or a child you simply cannot rouse are all reasons to call emergency services now.
When online advice can help with a child's fever
For a child over 3 months who is alert, drinking and settling between temperatures, a video consultation can help you find the cause, decide whether anything needs treating, and understand the specific signs that would mean seeking in-person care. The doctor can see the child on camera, assess breathing and hydration, and give you a clear, written plan. If any red flag is present, the honest answer is in-person assessment, and the doctor will say so.
How to bring a fever down, honestly
Paracetamol and ibuprofen lower a fever and ease the aches and misery that come with it, but they treat comfort, not the infection, and they do not make the illness pass any faster. In children, the guidance is to use these medicines to relieve a child who is distressed, not simply to force the number down, and they should not be given purely in the hope of preventing a febrile convulsion, which they do not reliably do.[1] Do not use paracetamol and ibuprofen at the same time as a routine; one is usually enough, and a doctor or pharmacist can advise on alternating only if the first has not helped a distressed child.
The measures that genuinely matter are simple: offer regular fluids in small amounts to prevent the person becoming dry, dress them in normal clothing rather than piling on or stripping off layers, keep the room comfortable, and let them rest. Do not sponge a child with cold water or use fans to force the temperature down, as this can be distressing and counterproductive. Watch the person, not just the thermometer, and use the warning signs above as your guide.
How doctors decide if a fever needs in-person care
Whether a fever is safe to assess online depends on the age of the person, how they look and behave, and what other symptoms are present. The table below shows how doctors sort fevers into self-care, online assessment and in-person or emergency care.
Swipe sideways to compare →
| Fever presentation | Likely first step | Suitable for online care? | When referral or in-person care is needed |
|---|---|---|---|
| Adult, fever under 3 days with an obvious cold or flu, otherwise well | Self-care, fluids and a written safety net | Usually yes | If it lasts beyond 3–5 days, keeps returning, or warning signs appear |
| Fever with a treatable focus (urine, throat, chest, skin) | Assess the source and prescribe if a bacterial infection is found | Often yes | Severe or spreading infection, or a poor response to treatment |
| Child over 3 months, alert, drinking, settling between temperatures | Find the cause, advise on comfort and a clear safety net | Often, for assessment and advice | Any red flag, dehydration, or a fever lasting 5 days or more[1] |
| Baby under 3 months with any fever of 38°C or above | Same-day in-person assessment | No | Always: urgent in-person review[1] |
| Non-blanching rash, stiff neck, breathing difficulty, drowsy or confused, or sepsis signs | Emergency care | No | Call 112 immediately[3] |
Not sure which row is you? A doctor can tell you in one consultation.
See available times →What the doctor checks in an online fever consultation
The assessment is a structured search for the cause, not a reading of the thermometer. In a fever consultation the doctor will typically check:
- How high, how long, and the pattern: when it started, whether it is climbing, easing or returning, and how it responds to paracetamol or ibuprofen.
- Where the infection might be: throat, ears, chest, sinuses, urine, tummy or skin, guided by your other symptoms.
- How unwell the person looks: alertness, breathing rate and effort on camera, skin colour, and whether a child is interacting normally between temperatures.
- Hydration: how much someone is drinking and passing urine, since dehydration changes the plan and the urgency.
- Red flags, deliberately: rash, neck stiffness, light sensitivity, severe headache, drowsiness, confusion or breathlessness are asked about directly.
- Recent travel and vaccinations: travel to areas with malaria or other imported infections shifts the assessment considerably.
- Risk factors: pregnancy, age, a weakened immune system, and long-term conditions that lower the threshold for in-person care.
When a fever is treated online, and when you need in-person care
Treated online: adults (18 and over) whose fever comes with a treatable or self-limiting cause and no warning signs; fevers with a clear focus such as a urine, throat, chest or skin infection that can be assessed and, where bacterial, prescribed for; and post-viral fevers that need reassurance, a safety net and a review point rather than a prescription.
In-person care: a fever of 38°C or higher in a baby under 3 months; a fever with a non-blanching rash, stiff neck, breathing difficulty, drowsiness or confusion; suspected sepsis at any age;[2] a fever after travel to a malaria region; and a fever with no clear source that persists or is climbing and needs blood tests or examination. In those cases the consultation gets you to the right care quickly rather than a prescription. Fever is one of many cold and flu symptoms the doctors assess online, and it often travels with a sore throat or tonsillitis that points to the cause.
When a fever needs in-person or emergency care
Seek same-day in-person care for a fever of 38°C or higher in a baby under 3 months, a fever that persists beyond about five days, or a fever in someone who is pregnant, elderly or has a weakened immune system and is getting worse. Call 112 immediately for a rash that does not fade under a glass, a stiff neck with dislike of light, severe breathlessness, a seizure lasting more than five minutes, or anyone who is floppy, unresponsive or cannot be woken. These can be signs of meningitis or sepsis, which are treatable but need emergency care fast.
Treating a fever at home: what helps and what does not
For adults, home care handles most short fevers: rest, plenty of fluids, light clothing, and simple pain-relief medicines that also lower temperature. A fever is the immune system working, and riding out two or three days of one alongside an obvious cold is normal.
What home care cannot do: it cannot find the cause. A fever with a stiff neck, a new rash that does not fade under a glass, confusion, breathlessness or severe pain anywhere is 112 territory, not home care. A fever that lasts beyond about three days, keeps returning, or arrives with urinary symptoms or a productive cough deserves a doctor, because those fevers usually have a treatable cause.
You do not have to leave home for that step either: a video consultation is at-home care with a licensed doctor in it, and if treatment is right for you, the prescription can be used at a pharmacy near you. You can see a doctor over video, usually within 15 minutes. Book a video consultation: no subscription, exact price before payment.
How Mobi Doctor works
- Book a time that suits you: open daily 7am–11pm CET. You can see a doctor over video, usually within 15 minutes. No subscription, exact price up front.
- Speak to a licensed doctor about fever: a private video call: you describe what you feel, the doctor asks what matters, and you agree the right plan together.
- Leave with your plan: everything agreed before you hang up: your plan, and a prescription to use at a pharmacy near you where medication is clinically right for you. If your doctor decides you need to be seen in person, you get a full refund.
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A fever can have more than one cause. Tick every symptom you have to see each condition page that mentions it. It finds the right page, not a diagnosis: a doctor gives you that on a video call.
Tap the body — an area or a point — to browse symptoms anywhere
Similar symptoms, different condition? Fever and Headache can start the same way. Compare them, or look up any other symptom in the full symptom checker.
Frequently asked questions about fever
What temperature counts as a fever?
A fever is generally a body temperature of 38°C (100.4°F) or above. Normal temperature is around 36.5°C to 37.2°C and shifts through the day, lowest in the early morning and highest in the evening. The exact figure matters less than how the person looks and behaves and what other symptoms come with the fever.
What causes a fever?
Most fevers are caused by infections: colds, flu, COVID-19, tonsillitis, ear, sinus, chest, urine and skin infections, and stomach bugs. A fever also follows vaccination for a day or two, and less often comes from inflammatory conditions, some medicines, blood clots, heat illness or, rarely, cancers. A fever is the immune system working, not an illness in itself, so the doctor looks for the source.
What are the symptoms that come with a fever?
A fever usually brings chills and shivering as the temperature climbs, sweating as it falls, aching muscles, headache, flushed skin, a fast pulse, tiredness, poor appetite and sometimes mild confusion in older people. The accompanying symptoms, such as a sore throat, cough, earache, burning when passing urine or a rash, point to the cause of the fever and steer the assessment.
How do I bring a fever down?
To bring a fever down for comfort, take paracetamol or ibuprofen (not both routinely, and never if unsafe for you), drink plenty of fluids, rest, wear light clothing and keep the room cool but not cold. Cold baths, sponging and alcohol rubs are not recommended; they cause shivering, which pushes the temperature up. The aim is to feel better, not to force the number to normal.
Can an online doctor prescribe treatment for a fever in Europe?
Yes, when the assessment finds a treatable cause. A fever itself is a symptom, so the doctor looks for the source, and where a bacterial infection such as a urine infection or tonsillitis is found, treatment can be prescribed, with the prescription sent to a pharmacy near you. A viral fever gets a symptom plan and a safety net rather than antibiotics.
How long should a fever last before I worry?
Most fevers with an obvious cold or flu settle within three to five days. Book a consultation if a fever lasts longer than that, keeps returning, climbs despite treatment, or has no clear source. Warning signs such as breathlessness, confusion, a stiff neck, a non-fading rash or severe pain mean in-person care now, whatever the day count.
Is a fever with no other symptoms serious?
A fever with no other symptoms in an adult is usually the start of a viral illness whose other symptoms appear over the next day or two. It deserves assessment if it lasts more than three days, if you have recently travelled to a malaria area, if you have a weakened immune system, or if you feel much more unwell than the temperature suggests; a urine infection is a common hidden cause.
Should I bring a fever down with paracetamol or ibuprofen?
Paracetamol and ibuprofen ease the aches and misery of a fever but do not cure the infection or shorten it. Use them to make a distressed person more comfortable rather than simply to lower the number, do not give both routinely, and check the doses on the packet. Ibuprofen is avoided in pregnancy, with stomach ulcers, kidney problems or dehydration.
When is a fever in a child an emergency?
A temperature of 38°C or higher in a baby under 3 months is urgent. At any age, call 112 for a fever with a rash that does not fade under a glass, a stiff neck, dislike of bright light, severe breathlessness, a fit, or a child who is floppy, very drowsy or hard to wake. Children are seen in person; consultations here are for adults.
Can I have a fever assessed online while pregnant?
Yes, and a fever in pregnancy is assessed promptly because the cause matters. The doctor looks for the source, advises that paracetamol is the usual first choice for comfort and that ibuprofen is avoided, and refers you for in-person care where the illness or its treatment could affect the pregnancy, such as a urine or kidney infection, flu or a high persistent fever.
Can you sweat out a fever, or does a fever help fight infection?
You cannot sweat out a fever: piling on blankets and heat only pushes the temperature higher. A moderate fever does help the immune system work, which is why doctors treat the discomfort rather than the number, but there is no benefit in letting a high fever run untreated when you feel miserable. Fluids, rest and light clothing matter more than sweating.
How can fevers be prevented?
Most fevers come from infections, so prevention is infection prevention: yearly flu vaccination, COVID-19 and pneumococcal vaccines if eligible, travel vaccines and malaria tablets where needed, hand washing, safe food and water, and treating urine and skin infections early. A short fever after a vaccine is expected and is not a reason to skip the next dose.
- Fever in under 5s: assessment and initial management (NG143), NICE, National Institute for Health and Care Excellence, 2019 (updated 2021).
- Sepsis: recognition, diagnosis and early management (NG51), NICE, National Institute for Health and Care Excellence, 2016 (updated 2024).
- Meningitis fact sheet, WHO, World Health Organization, 2023.
- Fever in under 5s, NICE CKS, Clinical Knowledge Summaries, reviewed 2024.
- Malaria fact sheet, WHO, World Health Organization, 2025.
- High temperature (fever) in adults, NHS, National Health Service (UK), accessed October 2026.
This page is for information only and is not a substitute for a medical consultation. Guideline links are provided for transparency; treatment decisions are made with your doctor.
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Read article →Speak to a doctor about fever over video, usually within 15 minutes
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