The term ‘fever’ means different things to different people and I prefer to refer to a ‘raised temperature’. Serious diseases such as encephalitis and viral and bacterial meningitis start off with fairly simple symptoms. Take measles, for examples. Measles can kill young children, and if it does not, can leave them with serious side-effects or complications such as hearing and visual defects, learning difficulties and brain damage.

4 Fahrenheit). If you think that your child has measles, or if temperatures stays at or goes over 38 Celsius, you should inform your doctor immediately.

With measles, the temperature starts to drop after a day or two, then increases again as the spots appear and go as high as 40C (104F). You should definitely have contacted a doctor by then, but if you have no thermometer you may not have noticed the increase in temperature.

An alternative safe method to this is the ear thermometer which measures the infrared heat emission from the eardrum. An infrared probe is inserted into the ear and the temperature measured. This is safe because the probe is too short to reach the eardrum, and is larger than an infants ear canal. This is the type of system employed in hospitals, and is available for purchase either online or from good pharmacies for from around £30 ($50). Forehead thermometers are also available, and traditional glass rectal thermometers can be used with infants by trained staff.