Professor Kristy Howells explains how to understand the effects of heat on children, and ensure they stay safe.

This weekend, temperatures across parts of the UK suddenly hit 31°C. And this week, they are staying high. For adults, it feels exhausting. For children, it can become something quieter. Harder to spot. More dangerous than we realise. Because heat stress in children is often silent.

It is the child who suddenly cannot concentrate. The teenager who keeps pushing through sport despite a pounding headache. The irritability adults dismiss as ‘bad behaviour’. The emotional wobble. The flatness. The exhaustion. The physiological strain builds long before collapse ever happens.

Children are not small adults when it comes to heat. Their bodies regulate temperature differently, they fatigue differently, and they are often poor judges of when their bodies are under strain.

Yet we still rely heavily on guesswork.

“Do they look too hot?” “Have they stopped?” “Did they ask for water?”

The problem is that children will often keep running, playing, competing and trying to keep up socially long after their bodies are struggling. Quietly.

This week, many children are also on half-term holiday. That means sports camps, playgrounds, artificial turf, beaches, bike rides, hours outdoors in peak temperatures, movement matters enormously for children’s wellbeing. But in a warming climate, we cannot keep treating heat as an afterthought.

Some simple but important considerations this week:

• Encourage hydration before children say they are thirsty.
• Shift more active play earlier or later in the day.
• Build in regular cooling and shade breaks.
• Be cautious with artificial surfaces, which can become significantly hotter than the air temperature.
• Watch for irritability, fatigue, headaches, dizziness, or emotional dysregulation, not just collapse.
• Understand that “they seem okay” is not always a reliable indicator of physiological strain.

Our recent work argues that children’s heat stress should be viewed not only as a medical issue, but as a safeguarding and educational challenge. Because the climate children are growing up in is changing faster than many of our schools, sports systems, and public spaces are adapting. This is also where wearable technology may become increasingly important.

Not to surveil children. Not to remove joy from movement. But to make the invisible strain visible. Heat literacy matters now. Children need help understanding hydration, pacing, recovery, shade, and how their bodies respond to heat and exercise. Because this is no longer just ‘hot weather’. This is becoming part of childhood itself.

Professor Kristy Howells is a Professor in Children’s Health and Movement in the School of Sciences, Psychology, Arts and Humanities, Computer Engineering and Sports.