Fever

A fever, also known as a high temperature or pyrexia, is when your body temperature is higher than normal. Normal body temperature varies between people and may fluctuate throughout the day, but it is usually around 37 °C. 

A fever is when your body temperature is 37.8 °C or higher.  

A fever isn’t an illness in itself, but a sign of another illness, usually an infection. Most infections thrive at a human body temperature of 37 °C, so increasing your temperature is one of your body’s ways of fighting the infection. Increasing the temperature also stimulates your body’s immune system. 

Fever may be caused by: 

• viral infections like colds, flu, and COVID 19
• bacterial infections like bacterial pneumonia, bacterial meningitis, and urinary tract infections (UTIs) 
• tropical diseases such as malaria 
• some chronic (long-term) conditions like rheumatoid arthritis and ulcerative colitis
• heat stroke

a side effect of some medications

You normally get a fever if you have an infection. Infections occur when bacteria, viruses, or other pathogens get inside your body through orifices like your mouth and nose, or a break in your skin. Many infections like colds, flu, and COVID-19 are spread from one person to another, or they may be picked up in the environment. 

Symptoms that may accompany a fever include: 

• feeling hot and sweaty
• feeling cold and shivery
• flushed skin that is hot to the touch 
• chattering teeth 
• feeling generally unwell 
• headaches 
• muscle aches
• loss of appetite
• weakness
• irritability 
• thirst and dehydration 

You can check to see if you have a fever by taking your temperature with a thermometer. Thermometers are available to buy from many shops and pharmacies. Make sure you follow the instructions that come with the thermometer carefully or ask your pharmacist how to take your temperature correctly. 

If you have symptoms of fever like feeling hot, sweaty, or shivery, you may still have a fever, even if the thermometer reading is below 37.8°C.

A fever is not usually dangerous, but it can be uncomfortable. Most fevers can be treated at home.  

Sometimes a fever can be a sign of a serious illness such as meningitis or malaria. 

You should see a doctor if you: 

• have a temperature over 39-40 °C

• • have a fever that lasts for more than 3 days 
  • you are shivering or have chattering teeth
  • have symptoms like hallucinations (seeing or hearing things that aren’t there) fast heart rate, neck stiffness, vomiting, and rash

• are drowsy or confused

• have a severe headache that doesn’t go away with painkillers 

• • are weak or lightheaded 
  • have severe muscle cramps

• have severe thirst, are peeing less than usual, or have stopped peeing

• have dark-coloured urine
• have symptoms that are getting worse
• have recently travelled to another country

Mild fevers can normally be treated at home. 

Some ways to treat fever yourself include: 

• If you feel uncomfortable or unwell, over-the-counter remedies like paracetamol and ibuprofen can help. Always read the patient information leaflet of any medication carefully and check with your GP or pharmacist that it is safe for you to take. Never take more than the recommended dose. 
• drink plenty of fluids, especially water
• avoid coffee, tea, and alcohol as they can make dehydration worse
• get plenty of rest
• sponge your skin with tepid (lukewarm) water. Avoid taking cold baths or showers as this can cause your blood vessels to constrict, trapping heat and making you feel hotter.

Fever in children

Fever is common in children and normally resolves by itself in a few days. Fever in children can be caused by infections such as colds and tonsillitis or a response to vaccination. 

If your child’s fever is mild, you can normally treat it at home by: 

• giving your child plenty of fluids
• keeping them home from school
• giving paracetamol or ibuprofen syrup that is suitable for children (always read the patient information leaflet of any medication carefully before use) 

See a doctor if your baby or child:

• has a temperature of 38°C or above

• is less than 3 months old 
• has other symptoms such as a rash
• has a fever that lasts 5 days or more
• is not eating
• has a fever that does not come down with medication
• has signs of dehydration such as dry nappies, sunken eyes, and no tears when crying 

Call an ambulance if your baby or child:

• • has a stiff neck
  • has a rash that doesn’t fade when a glass is pressed against the skin (the glass test) 
  • has a fit (seizure)
  • is upset or bothered by light
  • has pale or blue skin, lips, or tongue
  • has a high-pitched cry
  • is agitated and crying more than usual
  • is drowsy 

• has difficulty breathing
• is not feeding

Our GPs can help diagnose fever via video consultation based on your symptoms. They can also advise you on how to deal with your symptoms, look at possible causes of your fever and recommend any necessary treatments. 

Making an online video appointment is quick and easy at Medicspot. Simply click the link, choose a time and day that suits you, and have your consultation via video link from your phone wherever you are. 

Appointments are available Monday to Saturday from 9 am to 9 pm.

Your pharmacist can help with fever by giving advice on treating your fever at home and recommending over-the-counter medications that treat fever. Your pharmacist can also suggest what may be causing your fever and advise you on whether you need to see a doctor. 

Find a Pharmacy Near You

NHS: High temperature (fever) in adults April 6th 2020 (Accessed October 7th 2022)  

NHS Inform: Fever in adults May 19th 2022 (Accessed October 7th 2022)  

Medline Plus: Fever December 15th 2016 (Accessed October 7th 2022)  

Better Health: Fever June 21st 2022 (Accessed October 7th 2022)  

NHS: High temperature (fever) in children  June 1st 2020 (Accessed October 7th 2022)