Heat Illness
Heat can turn an ordinary day outdoors into a medical emergency. The tricky part is that heat illness often builds gradually: someone gets tired, irritable, or clumsy, and the group assumes they just need to push through. In the field, that assumption can be dangerous. Learning to spot heat illness early—and act promptly—matters just as much as carrying water.
First, know the difference between heat exhaustion and heat stroke. Heat exhaustion may bring heavy sweating, weakness, headache, nausea, dizziness, muscle cramps, or faintness. Stop the activity, move the person into shade or a cooler place, loosen excess clothing, and begin cooling them. If they’re fully alert and able to swallow, offer small, frequent sips of cool water or an electrolyte drink. Don’t make them gulp large amounts.
Heat stroke is a life-threatening emergency. Warning signs include confusion, unusual behaviour, poor coordination, collapse, seizures, or reduced consciousness. The skin may be hot, but sweating can still be present, so don’t use dry skin as a rule-out. Call emergency services immediately. Start rapid cooling while help is on the way: get the person out of the heat, remove unnecessary clothing, wet the skin, fan them, and use cold packs or cool water if available. If you can safely manage it, cold-water immersion is highly effective. Keep cooling and follow the emergency dispatcher’s instructions. Don’t give drinks to someone who is confused, vomiting, or not fully alert.
Prevention begins before the trail or workday gets demanding. Check the forecast, plan strenuous travel for cooler hours, and build in shaded rest stops. Drink regularly, guided by thirst and conditions, and replace salts as appropriate during prolonged sweating. Avoid forcing excessive water; drinking far more than the body needs can also be dangerous. Wear light, breathable clothing and protect your head and skin from direct sun. Give your body time to acclimatize over several days, especially after arriving in a hotter climate.
Finally, make heat checks part of your team routine. Watch for changes in pace, balance, mood, speech, and decision-making. A person may not recognize—or admit—that they’re becoming unwell. Agree in advance that anyone can call a halt without blame. If symptoms appear, stop and reassess rather than treating them as a test of toughness. Keep track of who is drinking, who is carrying extra weight, and whether the route still makes sense in the heat.
Heat illness is manageable when it’s recognized early, but it can become critical quickly. Slow down, cool the person, and treat confusion or collapse as an emergency. In survival situations, good judgement includes knowing when to change the plan. The safest progress is the progress that lets everyone keep thinking clearly and get home.
