Colds and flu are the most common causes of a raised temp-erature in children of all ages - in some cases, up to 105º F (40.6º C). One Baltimore, Maryland, study found that 7 per cent of parents believed temperatures would rise to 110º F (43.3º C) if left untreated, and that one in 15 caregivers thought it could rise to lethal levels in response to an infection. Also, 21 per cent believed that brain damage and other serious consequences could be brought on by a fever of 102º F (38.9º C) or less, while 14 per cent listed death as a potential outcome of fever (Pediatrics, 2001; 107: 1241-6).

However, in most children, the body doesn’t allow fever to spiral out of control (Pediatrics, 2001; 107: 1241-6; Pediatrics, 1992; 90: 846-50). In fact, it’s exceedingly rare for a child’s temperature to exceed 107º F (41.7º C).

Many parents fear that a fever could lead to meningitis or streptococcal sepsis. However, studies have found serious bacterial infection (bacteraemia) in just 1.6-3 per cent of children with temperatures of 102º F (38.9º C) or higher (Pediatrics, 2000; 105: 260-6).

The Baltimore study concluded that parents were in the grip of fever phobia - not surprising considering how many paediatric doctors also share the belief. At a Boston city hospital, 60 per cent of the paediatricians who answered a questionnaire believed that a temperature of 104º F (40º C) or higher could lead to seizures, brain damage or death (Pediatrics, 1992; 90: 851-4).

In fact, a fever is Nature’s defense against infection (Yale J Biol Med, 1986; 59: 89-95), and is often proof of an effective immune system.

Many animal investigations have shown enhanced resistance to infection with increased body temperatures (Ann Intern Med, 1994; 120: 1037-40). A fever can impede the spread of bacteria and viruses, improve survival rates and shorten disease duration in non-life-threatening infections (Microbes Infect, 2000; 2: 1891-904).

An analysis of 218 patients with bacteraemia showed an association between a high temperature on the first day of illness and the likelihood of surviving the condition (Ann Intern Med, 1994; 120: 1037-40).

Indeed, according to the Institute of Noetic Sciences (IONS) database, physicians in the early 1900s noted that, in some cancer patients, remission occurred after the patient developed a fever. In one case, a man with inoperable lung cancer had intermittent fever reaching 103º F (39.4º C) over a number of days. Within six months, his cancer was gone (J Thorac Cardiovasc Surg, 1964; 48: 984-90).

Convulsions Many parents panic when their child has a high fever because of a perceived link between fever and febrile seizures (FS). The abnormal jerking movements of a seizure can, indeed, be a frightening spectacle for parents to endure.

But most seizures (80-85 per cent) are benign and unlikely to lead to serious illness. A benign seizure usually lasts around five minutes or less, and rarely more than 15 minutes. Although they are the most common seizures in children three months to five years of age, they only affect 2-5 per cent of febrile children. They are generally brief and do not require treatment (Clin Pediatr [Phila], 1980; 19: 731-8; Pediatr Neurol, 2004; 2: 9-14; Ann Emerg Med, 2003; 41: 215-22).

Finally, a fever does not always lead to seizure. Although most children have temperatures of 102º F (38.9º C) or lower at the time of a seizure, many can tolerate higher temperatures without convulsing (Arch Intern Med, 2000; 160: 449-56). The fact is, there is no clear threshold over which fever leads to seizure.

Treating a fever Often, the discomfort of a fever causes the patient - or the parent - to try to lower the temperature. Yet, US studies found that those who took anti-fever medications such as paracetamol or aspirin for flu only prolonged their suffering - by an average of three and a half days more than those who took no medicines (Pharmacotherapy, 2000; 20: 1417-22).

And despite a lack of evidence that antipyretics can protect against seizures (Arch Intern Med, 2000; 160: 449-56), parents continue to give these drugs to febrile children. Indeed, paracetamol and ibuprofen are being inappropriately used, placing children at an unnecessary risk of toxicity (Pediatrics, 2001; 107: 1241-6).

In one randomised study of over 84,000 children, around 1 per cent of those taking either ibuprofen and paracetamol were hospitalised. Four of the children taking ibuprofen had gastrointestinal (GI) bleeding. Indeed, the risk of hospitalisation for GI bleeding with ibuprofen was 7.2/100,000 population (JAMA, 1995; 273: 929-33). Although no child in that study was hospitalised for GI bleeding with paracetamol, parents should nevertheless be aware of the dangers of overdosing (Pediatrics, 2001; 107: 1241-6). In 71 cases of paracetamol-induced liver toxicity, 30 per cent were the result of accidental overdose in patients using the drug for pain relief (N Engl J Med, 1997; 337: 1112-8).

However, treating a fever doesn’t have to include drugs. One relatively successful treatment is sponging with ice water or alcohol water. But note: alcohol can cause dehydration and hypoglycaemia in young children (Pediatrics, 2001; 107: 1241-6).

Sponging with tepid water can also work (Cochrane Database Syst Rev, 2003; 2: CD004264), and is reportedly more comfortable for the patient (J Pediatr, 1970; 77: 824-9). However, it could interfere with the natural healing process and prolong illness.

So, it appears that if a child - or adult - has a fever from a winter cold or flu, it may be best to just leave it be. It may well be the body’s own best medicine.

Amanda Diamond