As temperatures soar, the risk of heatstroke rises sharply, and knowing the difference between heat exhaustion and heatstroke can save lives. The NHS warns that heat exhaustion is an early signal that your body is struggling, and if ignored, it can quickly escalate to heatstroke—a life-threatening condition. Recognising the warning signs and acting fast is crucial for staying safe in the sun.
Heat Exhaustion: The Warning Signs
Heat exhaustion occurs when your body overheats and struggles to cool down. According to NHS guidelines, common symptoms include heavy sweating, an increased heart rate, dizziness, lightheadedness, unusual tiredness, pale and clammy skin, muscle cramping, headaches, and nausea or vomiting. These signs mean your body is losing the battle against the heat, and you need to cool down immediately.
Many people assume that heatstroke always involves profuse sweating, but the NHS clarifies that in advanced heatstroke, the body's sweating mechanism shuts down completely, leaving the skin hot and dry. This is a critical distinction that can help you identify a medical emergency.
Heatstroke: A Medical Emergency
Heatstroke is a severe condition that requires immediate medical attention. Symptoms include unusual behaviour, confusion, anxiety, difficulty speaking or slurred words, collapsing, loss of consciousness, and seizures or fits. If you suspect heatstroke, call 999 immediately. While waiting for help, move the person to shade and start active cooling methods, such as applying cold water to the skin and fanning.
The NHS recommends the '30-minute rule' for helping someone suffering from heat-related illness: cool them down by moving to shade, removing extra clothing, and giving fluids. If there is no improvement after 30 minutes, call emergency services. Additionally, the 'sweat test rule' helps distinguish between heat exhaustion and heatstroke: profuse sweating indicates heat exhaustion, while dry skin, rapid breathing, and neurological confusion point to heatstroke.
Expert Tips for Staying Cool
Gilad Zilberman of ticket platform SeatPick emphasises preparation for outdoor events. "Hydration is key, but drinking too much plain water can dilute sodium levels, leading to hyponatremia," he says. Instead, sip water regularly throughout the day, and mix in electrolyte sachets and salty snacks to replace minerals lost through sweat.
When packing for a day out, Zilberman suggests bringing a frozen water bottle, handheld fans, electrolyte tablets, an umbrella for shade, and a microfibre towel to soak and drape over pulse points. Keep these items accessible in your bag to avoid rummaging in a crowd.
Smart Habits to Beat the Heat
Setting a repeating alarm on your phone to check in with yourself hourly can help prevent overheating. Use the reminder to drink water, eat a snack, rest in the shade, and reapply sunscreen. If your phone shows an overheating warning, take it as a cue that you might be overheating too.
Fans are popular, but they only work effectively if used correctly. Direct airflow toward pulse points—neck, wrists, inside of elbows, and behind knees—where blood vessels are close to the skin and sweat evaporates efficiently. However, note that electric fans lose effectiveness when the ambient temperature exceeds 35°C (95°F), as they merely circulate hot air. In extreme heat, prioritise shade, ice, and water over fans.
Always consult the NHS Heat Exhaustion and Heatstroke Guidelines for official advice, and remember: when in doubt, seek medical help. Heatstroke is preventable with awareness and proactive measures, so enjoy the sunshine safely.
