November 2025 - Magazine - Page 132
Mi n i str i es
OUT of TIME
when it goes above 40C (104F), and can lead to hallucinations, febrile seizures and death.
Fever's payoff
While fever involves a regulated rise of our internal thermostat (the set point), during hyperthermia the body temperature rises in an uncontrolled way outside of thermoregulatory
control. If the perceived threat to the body is defeated, the fever will break. The end of a
bout of fever comes when the body has been successful in fighting off an infection, either
by itself or with the support of modern medicine, such as antibiotics for bacterial infections.
Fever's payoff comes from its short-term nature, as the many systems in our bodies require a
return to that sweet spot of around 37C (100F) to operate at an optimal level.
Fever is a pillar of inflammation, which is our bodies' natural response to harms such as injury
or infection. Fever, alongside pain, redness, oedema (a build-up of fluid characterised by
swelling) and loss of normal function, occurs in affected body parts and systems when your
body responds to those threats. Together, these reactions ensure our bodies respond
promptly to the danger, whether it is an infectious or a non-infectious risk, says Perretti.
Young children get fevers for the same reasons as adults, often linked to viral or bacterial
infections. But they are more susceptible to them, largely because they take longer to calibrate their internal thermostat. What's more, in children, the hypothalamus 3 a region of the
brain which produces hormones that regulate body temperature 3 is still getting used to responding to pyrogens, substances that trigger an immune response that leads to a rise in
temperature.
Pyrogens communicate with the hypothalamus (the region of our brains which regulates
the temperature of our bodies), to raise our temperature to a level at which viruses and
bacteria struggle to replicate and survive. These microbes tend not to adapt to higher temperatures during bouts of fever, however, since it isn't beneficial to them in the long-term 3
they would become less efficient at infecting healthy, cooler organisms.
Millennia-long benefit
Despite centuries of trying to get rid of fevers, scientists now understand that in many circumstances their benefits can actually outweigh their harms.
When someone has a fever, the increase in temperature can support immune cells, such as
white blood cells, helping them to respond faster to the threat of pathogens. Fevers can also benefit the biochemical and cellular reactions which are part of the body's inflammatory
response, says Perretti. As well as turning the thermostat up above the temperature pathogens such as bacteria tend to thrive in, the heat element of a fever works as an alert system, igniting our inner surveillance team into action: our neural pathways and physiological
systems chat to each other, conjuring the best plan of action.
Our changes in behaviour during a fever also help to supercharge our body's immune response, says Perretti. Along with other aspects of how our bodies fight an infection, such as
