High temperature, fever, chills, or any other name you give it, is a sure sign that your body's immune system is at work trying to fight something off. The common causes of a high temperature are viruses or bacteria causing infection, but there are many other causes. You will normally feel unwell with a fever, and may be swinging from feeling cold and shivery and getting under the duvet to burning up and feeling hot and sweaty. You may have a hot head, chest or back when you put a hand to it.
If you have a thermometer that shows a temperature on or above 38°C (100.4°F) then you have a documented fever. This is likely the cause of an infection or inflammatory process going on in the body.
Starting simple is the best way to get well soon. Make sure you get lots of rest and take paracetamol or ibuprofen if you are feeling unwell, as this will bring the fever down. Keeping hydrated is essential, and with a fever, you lose more fluids than usual. You should aim to drink at least the usual recommended daily fluid, and increase your intake if your urine is darker than a pale straw colour.
If you are not sure of the cause of your fever, it would be best to speak with your doctor. If you have had a fever for more than five days, severe pain in your tummy, joints, head or anywhere else, new rashes, shortness of breath, confusion or a new headache, or you feel bothered by bright lights or your neck feels stiff to move, then you should seek urgent medical advice.
The doctor will ask about your symptoms and examine you. Depending on the possible diagnosis, blood tests, urine tests or imaging (for example a chest X-ray) could be carried out, or you may be referred to a specialist department. The doctor may also prescribe some medication such as pain relief or antibiotics to help with your symptoms.