Biological factors mean a child’s core temperature rises faster than an adult’s – and that can result in a medical emergency
Children and babies are more vulnerable in heatwaves than healthy adults. As temperatures rise again, how do we keep children safe?
The biological systems that regulate heat in the human body are controlled by a region of the brain called the hypothalamus. It is the body’s master thermostat, acting to keep our internal temperature around 37C. It also detects when we need more fluids.
When the hypothalamus detects a rise in temperature, it initiates responses such as sweating, which cools the body through evaporation, or vasodilation, which directs warm blood to vessels near the surface of the skin, where heat can radiate away.
But in children, particularly those under the age of five, the hypothalamus is not fully developed. They sweat less and do not realise when they are thirsty.
Also, children’s smaller physical size gives them a substantially greater body surface area-to-mass ratio than adults, meaning they absorb heat faster. They are also more likely to be physically active, and less likely to pace themselves, giving them much higher rates of metabolic heat production compared with adults.
All these factors mean children’s core temperatures rise faster, and stay high, compared with an adult.
If a child has been out too long in the sun, they may begin to develop heat exhaustion. They may sweat excessively, their skin may appear pale and clammy, and they may become dizzy, irritable or intensely thirsty. In more serious cases, they may begin to suffer muscle cramps and nausea, or even start vomiting.
At this point it is important to act, encouraging your child to come to a cooler, shaded spot, to have cold drinks, and to cool them down with wet towels or water, because the next stage – heatstroke – is even more severe.
According to the British Red Cross, heatstroke occurs when someone becomes so hot their brain’s thermostat fails. A child with heatstroke may have hot, flushed and dry skin, a headache, worsening confusion and restlessness, and a body temperature of more than 40C. He or she may lose consciousness. It is a medical emergency.
Overheating carries particularly serious health risks for children under five, and it is especially dangerous for babies, increasing the risk of sudden infant death syndrome (Sids).
During the June heatwave in the UK, one in six babies were living in overheated homes, according to research by housing activists. Some parents were going as far as booking air-conditioned hotel rooms to keep their children cool.
“Things to think about when it comes to children in heatwaves include: ensuring children stay well-hydrated; encouraging rest in cool, shaded areas; dressing children in light, loose-fitting clothing; and monitoring for signs of heat distress, such as fatigue, dizziness, or nausea,” said Dr Jessica Mee, an expert in heat physiology at the University of Worcester.
Babies, in particular, need special treatment, since they are so reliant on adults to make adaptations for them. In very hot weather, they may need extra breast or bottle feeds. They should not be left to sleep in their pram, which can become hot and airless, and when they are put down to sleep, parents should ensure there is good air circulation around them.
If you have a newborn, the National Health Service recommends keeping their room at a temperature of between about 16C and 20C.