Fever and body temperature — Health, 11–13 years
How the body raises its temperature during illness, and how to respond without guessing from touch alone.
What fever means
Fever is a raised body temperature caused by the body changing its internal temperature setting, often during an infection. It is a sign, not a disease by itself. Feeling hot, cold or shivery can happen, but only a correctly used thermometer gives a useful measurement.
Why the body raises heat
When the immune system detects a threat, it can raise the body’s set point. The higher temperature may make conditions less comfortable for some germs and helps immune reactions work. The problem is deciding how ill someone is: the number matters, but alertness, breathing, pain and how long it lasts matter too.
Checking a fever
Alex feels shivery after school. First, an adult checks the thermometer instructions and measures the temperature correctly; touching Alex’s forehead is not enough. The reading is 38.5 °C, so Alex rests, drinks normally and is observed. The adult contacts a health professional if Alex becomes hard to wake, struggles to breathe, has severe pain, or the fever persists as advised.
The number trap
A reasonable mistake is treating one temperature number as a complete diagnosis. People want a clear threshold, and a thermometer seems precise. But readings vary with the method and time, while serious illness can occur without a very high fever. Look at the whole person and ask an adult for help when warning signs appear.
When to seek help
Fever is useful information when deciding whether to rest, stay away from others while ill, or contact a health professional. At home, an adult can record the time, temperature and symptoms so changes are easier to explain. Urgent help is needed for trouble breathing, blue or grey skin, confusion, a seizure or a person who is difficult to wake.
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