Fever – Adults

Fever is an abnormally high body temperature of over 37.8 C
(100 F) orally or 38.2 C (100.8 F) rectally. For children, see the
Fever – Children topic on the Healthpoint.

DESCRIPTION

Average body temperature is around 37 degrees Celsius/98.6
degrees Fahrenheit. Readings slightly outside this range are
normal. During a 24-hour period a person’s body temperature will
naturally change. Low body temperature usually occurs in the early
morning and increases during the day to reach a high point in the
late afternoon. A Fever most commonly develops as a result of a
bacterial or viral infection. Other causes of Fever or a raised
temperature include exercising, wearing too many clothes, hot
weather or having a hot bath. 

WHAT IS HAPPENING?

Body temperature is controlled in a part of the human brain
called the hypothalamus. This is the body’s thermostat. When the
immune system senses an infection or other trigger, it releases
substances called pyrogens. The pyrogens act indirectly on the
hypothalamus, causing it to raise the temperature of its
thermostat. The body then reacts to conserve and produce heat,
causing the temperature to rise. Blood vessels near the skin
surface constrict and shivering begins, so as to prevent heat loss
from the body.

When the invading disease or trigger has been controlled by
the body or antibiotics, the temperature setting in the
hypothalamus will drop to the normal level. The body then needs to
cool itself to return to the new setting in the brain. The skin
becomes flushed and warm, and the person begins to sweat.

BENEFITS AND RISKS

In some ways a Fever can be beneficial. Fever triggers the
release of substances from cells in the body, which boost the
activity of the immune system. A high body temperature may also
help to prevent the growth of some types of bacteria. Fever
increases the heart rate, which causes the cells involved with
immunity (white blood cells) to act more effectively and be
delivered more quickly to the sites of infection. Heat speeds up
the rate of chemical reactions and a Fever may help body cells to
repair more quickly during illness. However, Fever that is very
rapid, high or prolonged and/or does not respond to treatment can
result in dehydration (excess fluid loss from the body), excess
acid build-up in the body and brain damage.

TREATMENT OPTIONS

Always consult your Doctor for diagnosis and advice. In no way
is this information intended to replace the advice of a registered
medical practitioner.

• Paracetamol or ibuprofen can reduce Fever. 
• It is important to drink plenty of fluids, as Fever can cause
  dehydration.
• Avoid trying to cool the skin with cold face washers etc, as
  this may cause shivering which can increase the body
  temperature.
• Fever caused by hot weather or physical exercise will not
  respond to paracetamol or ibuprofen. Instead, treatment involves
  cooling the person immediately by removing them from the hot
  environment, removing their clothes, using a wet sponge and a fan
  to cool the body. Seek emergency assistance if the person is
  confused or unconsciousness.

Seek medical assistance immediately if you experience any of
the following symptoms with a Fever:

• A temperature of or greater than 104°F/40°C. 
• Fever that lasts more than 7 days. 
• If the symptoms get worse. 
• Confusion or excessive sleepiness. 
• Stiff neck. 
• Severe headache. 
• Sore throat. 
• Rash. 
• Chest pain. 
• Trouble breathing. 
• Repeated vomiting. 
• Abdominal pain. 
• Blood in the faeces.
• Pain with urination. 
• Leg swelling. 
• Red, hot, or swollen area of skin. 

People with serious medical illnesses, such as cancer or HIV,
may not show these warning signs and should seek medical assistance
immediately if they develop a Fever.

DIET HINTS

• Drink plenty of fluids, as Fever can cause you to become
  dehydrated.
• Soups and fresh fruit and vegetable juices are highly
  nutritious and easy for the body to digest. 
• Try to avoid drinking beverages containing caffeine e.g.,
  coffee, tea and cola drinks, as this chemical can promote
  dehydration by increasing the volume of urine.
• Solid foods can be eaten in small amounts. Lightly cooked
  (steamed) vegetables and fruits are easy to digest and are a
  healthy sources of vitamins and minerals.
• Avoid eating highly processed, fatty and sugary foods as these
  are difficult to digest during Fever. 
• Include plenty of fresh garlic, onions and ginger in the diet.
  These add a pleasant taste to food and valuable nutrients and
  promote sweating which helps to cool the body.

PHARMACIST’S ADVICE

Ask your Pharmacist for advice.

1. Follow the Diet Hints.
2. Your Pharmacist can recommend the best way for you to monitor
   your temperature e.g. with a thermometer or temperature strip.
3. Certain pain relieving drugs help to reduce Fever e.g.
   paracetamol or ibuprofen. Ask your Pharmacist for
   advice. 
4. Try to avoid physical exertion and stress during a Fever, as
   these factors may aggravate the symptoms. Rest helps the body to
   heal more quickly.
5. Drink plenty of fresh, filtered water. A rise in body
   temperature increases the body’s requirements for fluids. Try to
   avoid drinking beverages containing caffeine e.g.,coffee, tea and
   cola drinks, as this chemical can promote dehydration by increasing
   the volume of urine. Ask your Pharmacist about the different types
   of water filters which are available.
6. If the diet is inadequate, consider some nutritional
   supplements. Vitamin C, garlic and echinacea have properties which
   help to boost the immune system and aid in the recovery
   process.