Fever: symptoms, treatments, types, and causes

Fever: symptoms, treatments, types, and causes




Using an oral thermometer is the most popular way to take your temperature. Before using the thermometer, you should clean the probe with cold water and soap, before rinsing it.


Put the thermometer under your tongue, right to the back of your mouth. Turn it on; it will beep. Close your mouth and wait until the thermometer beeps again to check the display.


Ear thermometers are another popular choice for taking your temperature.


Pull your ear up and back, before putting it inside your ear canal. Be careful not to push it in too far. Turn it on, it will beep. The second beep indicates that the reading is ready.


How to tell if you or your child has a temperature without a thermometer


Fevers make people feel hot or cold. You may look flushed, or be shivery, which are indicators that your body is actively trying to lower your temperature.


If possible, have someone else touch your forehead with the back of their hand. Get them to touch their own forehead first, before yours, as it will give them a good indicator of whether you feel hot.


When it comes to diagnosing your child with a temperature – without a thermometer – they may also experience:


  • Irritability
  • Lethargy
  • Flushed or pale skin
  • Difficulty swallowing
  • Refusal to drink or eat.


What is a normal temperature?


The normal body temperature for an adult is around 37°C. However, every person’s base body temperature is slightly different, and may be slightly higher or lower.


The table below gives the normal ranges of body temperature for adults and children by type of thermometer reading:


Type of reading

0–2 years

3–10 years

11–65 years

Over 65 years























What is a high temperature in adults?


A mild fever is 37.8°C
A high fever is 39.5°C
A very high fever is 41°C


What is a high temperature in a child?


It is the same as adults (see above). A high temperature is more common in young children as they fight off infections such as coughs and colds.


What is a fever?


A fever is your body’s natural response to fighting off common illnesses, such as flu, tonsillitis, colds and urine infections. It is also one of the most common symptoms of coronavirus.


The high temperature helps your body to fight infection by stimulating your immune system. When your body’s temperature is increased, it is harder for the virus to survive.


If you have a fever, or a new continuous cough, you should self-isolate for 7 days.


What if you have a low body temperature?


A low body temperature normally occurs if you have been in cold weather. However, it can also be caused by alcohol or drug use.


Diabetes and a low thyroid can also cause a low body temperature.


Several factors can lead to a lower body temperature in older people. For instance, as you age, you lose fat under the skin in your extremities and your skin becomes drier; both of these changes cause loss of body heat. Metabolism, which also generates heat, tends to slow as you age. Medications, including beta blockers and antipsychotic drugs, also may lower body temperature, as can an underactive thyroid gland.


How should you treat a temperature?


There are a number of things you can do to treat a fever at home.


Firstly, wear loose-fitting, comfortable clothing and make sure the room you’re in isn’t too warm. Secondly, drink plenty of fluids.


It is also acceptable to take paracetamol, as it will reduce the fever.


Why else might you have a high temperature? (Other than COVID-19)


It is important to note that if you have a fever, you must self-isolate under government guidelines – it is one of the most common symptoms of COVID-19.


However, there are many other reasons that you may have a temperature. Therefore, if you do have a temperature, don’t panic, as this may increase your anxiety levels. Anxiety can cause symptoms which can feel similar to COVID-19.

Other reasons for a high temperature include:


  • Being hungover
  • A poor sleep the night before
  • Heat exhaustion
  • Taking medication
  • A bacterial infection
  • Earache
  • Strep throat
  • Urinary tract infection
  • Common cold or flu


Common symptoms of anxiety/a panic attack include:


  • Feeling faint
  • Sweating
  • Chills
  • Dry mouth
  • Pins and needles in limbs
  • A churning stomach
  • Dizziness
  • Hot flushes
  • Shortness of breath
  • Chest pain


When should you seek medical attention with a high fever?


According to NHS guidelines, you should seek medical attention if any of the following symptoms accompanies a fever:


  • Severe headache
  • Unusual skin rash, especially if the rash rapidly worsens
  • Unusual sensitivity to bright light
  • Stiff neck and pain when you bend your head forward
  • Mental confusion
  • Persistent vomiting
  • Difficulty breathing or chest pain
  • Abdominal pain or pain when urinating
  • Convulsions or seizures


Can you have coronavirus without a temperature?


It is possible to have coronavirus without a temperature. It occurs in 75% of cases. This is particularly the case in the first few days of having the virus. It is also possible to have no symptoms at all.

Paul Kelly - Medical Content Writer
James O'Loan - CEO & Prescribing Pharmacist
James O'Loan , CEO & Prescribing Pharmacist on 17 September 2021
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