It used to be that the British summer brought a few welcome weeks of sunshine, just enough for an ice cream on the pier, a barbecue in the garden, or perhaps a trip to Brighton beach. But those days of mild and manageable summers have changed. Climate data shows that the UK is getting warmer, with summers now presenting serious health risks. Among the most dangerous and underestimated of these risks is heat stroke.
Heat stroke, which was traditionally associated with tropical regions or desert climates, is now increasingly seen within British shores. The summer of 2025, for instance, has already seen temperature surges above 35°C in parts of London, Kent, and the Midlands. The UK Met Office has issued multiple heat alerts, and hospitals across the country are quietly preparing for seasonal surges in heat-related admissions. What was once rare is becoming routine and the shift calls for awareness, preparation, and timely response.
What Is Heat Stroke and How Does It Happen?
Heat stroke is a severe, life-threatening condition that occurs when the body’s internal temperature regulation fails. Under normal circumstances, our bodies keep cool primarily through sweating. When it’s hot, we sweat; the moisture evaporates and cools us down. However, during extreme heat, particularly when accompanied by high humidity, this cooling system can break down. In cases of heat stroke, the body’s core temperature can rise above 40°C (104°F), leading to cellular breakdown, organ failure, and even death if not promptly treated.
There are two principal types of heat stroke. The first is classic (non-exertional) heat stroke, which generally affects vulnerable populations such as the elderly, infants, or those with chronic health conditions. These individuals may be indoors but unable to keep cool due to poor ventilation or lack of mobility. The second type, exertional heat stroke, affects otherwise healthy people who engage in intense physical activity in hot environments, e.g, athletes, construction workers, or even festival-goers dancing under the midday sun.
Why is the UK Heat Increasing?
The rise in UK heat stroke cases is not just anecdotal. Public Health England has consistently reported excess deaths during heatwaves, with the 2022 summer heatwave alone responsible for over 2,800 additional deaths. Many of these were in individuals over 65, especially those living alone or in urban flats that turned into virtual ovens. This worrying trend is underpinned by broader climate shifts, with the last decade producing some of the UK’s hottest summers on record.
Our infrastructure, especially housing, has not caught up. Many British homes are designed to conserve heat, not to dispel it, making them vulnerable during prolonged hot spells. Combined with an aging population, growing urbanisation, and limited public awareness, the country finds itself underprepared for the realities of a hotter future.
How and When Does Heat Stroke Strike?
Understanding the causes of heat stroke is vital to prevention. At its core, heat stroke results from a failure to regulate temperature. This can be triggered by prolonged exposure to high external temperatures, by engaging in strenuous activity, or by underlying physiological or environmental conditions that inhibit cooling. Dehydration plays a major role, as it limits the body’s ability to produce sweat. Certain medications, such as diuretics or antidepressants, can impair thermoregulation, as can pre-existing medical conditions like cardiovascular disease, obesity, or diabetes.
Most cases occur during peak sun hours, typically between 11 a.m. and 4 p.m. especially on days with minimal cloud cover or wind. However, the greatest danger arises during sustained heatwaves, when nighttime temperatures remain high. Without adequate cooling during the night, internal body temperatures and indoor environments become increasingly difficult to manage. It is often by the second or third day of a heatwave that we see spikes in hospital admissions and emergency calls.
Symptoms of Heat Stroke
Recognising the symptoms of heat stroke early can be the difference between life and death. The condition typically presents with an abnormally high body temperature, altered mental states such as confusion, dizziness, or agitation, a racing pulse, and hot, often dry skin. The affected person may stop sweating altogether or continue to sweat profusely, depending on the type of heat stroke. In extreme cases, seizures or loss of consciousness may occur. These symptoms reflect the body’s systems being overwhelmed and beginning to shut down.
It is worth noting that children, older adults, and those with communication difficulties may exhibit less obvious signs such as fatigue, irritability, or fainting which may be misinterpreted or ignored until it is too late.
Treatment
When heat stroke is suspected, time becomes critically important. The first step should always be to call emergency services. While awaiting medical help, it is crucial to begin cooling the individual as rapidly as possible. This might involve moving them to a shaded or air-conditioned space, applying cold compresses to the neck, armpits, or groin, or even immersing them in cool water if available and safe to do so. However, if the person is unconscious or disoriented, it is dangerous to give them fluids by mouth, as this could lead to choking.
At the hospital, treatment typically includes advanced cooling methods, intravenous fluids, and monitoring for organ damage. Recovery can take days or even weeks, depending on the severity. In severe cases, heat stroke can leave lasting effects on the brain, kidneys, or cardiovascular system.
Prevention
The good news is that heat stroke is preventable. Simple behavioural adjustments can go a long way in protecting against its onset. Staying hydrated is paramount, especially during hot days. People should aim to drink water consistently, not just when they feel thirsty. Alcohol and caffeine should be limited, as both can contribute to dehydration. Dressing appropriately with light, breathable fabrics and wide-brimmed hats helps the body manage external heat, while limiting strenuous activities during peak heat hours significantly reduces risk.
For those living in urban or poorly ventilated housing, the use of fans, blackout curtains, and even improvisational cooling tricks such as placing a bowl of ice before a fan can improve indoor comfort. There is a communal responsibility as well. Vulnerable individuals particularly the elderly and socially isolated, should be checked on regularly during heatwaves. Children and pets should never be left in parked vehicles, not even for a few minutes, as temperatures inside can soar dangerously in no time.
Finally,
From a broader public health perspective, the rising incidence of heat stroke is both a symptom and a warning. It reflects not just the physical toll of climate change but also the inadequacy of our infrastructure and public systems to adapt. Schools, care homes, hospitals, and public transport systems all require updated heat management strategies. Urban planning must now consider heat islands and thermal comfort just as seriously as traffic or green space.
The message is clear. Heat stroke is no longer a distant or rare phenomenon. It is a pressing reality of British summers, one that demands respect, awareness, and preparation. This summer, as we revel in the rare joy of sunshine, let’s also be mindful of its dangers. Let’s drink more water than we think we need, rest more than we feel we should, and check on those who may not know they’re at risk. A summer well spent is one where everyone returns from the sun safe, refreshed, and unharmed.
If we treat heat stroke not just as a medical issue but as a public responsibility, we can save lives and turn hot summers from health hazards into moments of warmth and well-being.