Heat illness: recognising and treating heat exhaustion and heatstroke

Heat illness is a spectrum, and knowing where someone sits on it decides your response. At the mild end are heat cramps and heavy sweating during activity: stop, rest in shade, sip water or oral rehydration salts. Heat exhaustion is the middle stage: heavy sweating, weakness, cold clammy skin, headache, dizziness, nausea and a fast weak pulse. Treatment is straightforward and works: move to shade or air-conditioning, lie the person down, loosen clothing, cool the skin with water and fanning, and give sips of water or rehydration solution if fully conscious. Most people recover within 30-60 minutes; if not, or if they vomit and cannot keep fluids down, get medical help. Heatstroke is the emergency: body temperature above 40°C, confusion, slurred speech, agitation, seizures, hot skin (sweaty or dry), or loss of consciousness. This can damage organs and kill within the hour, so call 1669 immediately, move the person to the coolest available place, and cool them aggressively while waiting: soak clothing or skin with water, fan continuously, put cold packs or wet cloths on the neck, armpits and groin. Do not give fluids to a confused or unconscious person. Risk is highest for older travellers, young children, anyone dehydrated, and people drinking alcohol in the sun. Prevention (see the safety category): hydrate beyond thirst, SPF 50+ and a hat, avoid midday exertion, and build in shade breaks. If you feel yourself getting dizzy or stop sweating in the heat, take it as the warning it is.

Summary

In Koh Samui's heat and humidity, heat illness ranges from uncomfortable (cramps, exhaustion) to life-threatening (heatstroke). Learn the difference: exhaustion means heavy sweating, weakness and nausea, treat with shade, cooling and fluids; heatstroke means confusion or collapse, call 1669 immediately and cool the person aggressively.

Key facts

• Heat exhaustion: heavy sweating, weakness, nausea; treat with shade, cooling, fluids
• Heatstroke: confusion, collapse, temperature above 40°C; call 1669 immediately
• Cool aggressively while waiting: water, fanning, cold packs on neck/armpits/groin
• Never give fluids to a confused or unconscious person
• Older travellers, children, dehydration and alcohol raise risk sharply

Local tips

• Oral rehydration salts from any pharmacy beat plain water after heavy sweating
• Plan exertion before 10:00 or after 16:00 in hot months
• Check on older travel companions during heatwaves; they may not notice symptoms
• If someone stops sweating in extreme heat, treat it as an emergency warning