Dizziness, nausea, lack of sweating or confusion in high heat — move to shade immediately, remove clothing and apply cool water to cool down; do not give water to anyone who is unconscious, call 120 right away

Cost: No cost at all.
In plain terms: Red, hot skin, slurred speech and confusion are signs of heatstroke. It can take just minutes for someone to go from feeling dizzy to losing consciousness, and the mortality rate is very high. Immediately move the person to a cool, well‑ventilated area, strip off their clothes and use cool water or wet towels to bring their temperature down while calling 120. Never give water to someone who is unconscious — it can cause choking.
Benefit: The U.S. National Weather Service describes heatstroke as a “serious medical emergency.” Its symptoms include a body temperature above 103°F (39.4°C), confusion, slurred speech and hot, red skin. The recommended response is to call emergency services, move the person to a cool place and apply cool water or wet cloths — “do not give any fluids.” Heat exhaustion shows up as heavy sweating, weakness, cool and moist skin, and a rapid but weak pulse; treatment involves moving to shade, loosening clothing and sipping water; seek medical help if vomiting occurs, condition worsens or symptoms persist beyond an hour. The Yunnan Provincial Center for Disease Control warns to relocate to a cool, breezy spot, use cold wet towels, give salt‑containing drinks to conscious victims and call emergency services for severe cases — heatstroke carries an extremely high fatality rate. The Chinese CDC advises cooling first, then transporting; the “golden half‑hour” after loss of consciousness is critical for effective cooling. Healthy young adults without underlying conditions may safely be immersed in cold water for rapid cooling, while the elderly and those with chronic illnesses should have cool water sprayed on their skin to promote evaporation. The Wilderness Medical Society’s 2024 heat‑related illness guidelines list cold water immersion as the fastest and most effective method for severe heatstroke; if ice water isn’t available, any cool water will do, and if immersion isn’t possible, spraying water while fanning can achieve roughly half that cooling rate.
Evidence grade: B
Sources:US National Weather Service. Heat Related Illnesses. https://www.weather.gov/safety/heat-illness ; 云南省疾控局 (2026). 出现这些症状，你可能是中暑了. https://ynsjkj.yn.gov.cn/html/2026/jikongkepu_0719/2606.html ; 中国疾病预防控制中心. 高温天气，中国疾控中心提醒您谨防中暑：「如有条件可用冷水浸泡的方法对无基础疾病的青壮年快速降温。老人和有基础疾病的患者可向皮肤喷水通过蒸发降温。降温应遵循"先降温，后转运" 的原则」. https://www.chinacdc.cn/jkkp/ggws/hjyssj/202409/t20240906_296985.html ; 国家卫生健康委 (2010). 高温中暑预防知识要点. https://www.nhc.gov.cn/wjw/jbyfykz/201007/1edb19b7dd4e4bdf8da5ea45f4a64e23.shtml ; Eifling KP 等 (2024). Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Heat Illness: 2024 Update. Wilderness & Environmental Medicine 35(1_suppl):112S-127S. https://doi.org/10.1177/10806032241227924（正文站点拒绝自动抓取，具体推荐按荒野医学会官网的更新摘要核对：「cold water immersion … is the most important method of treating severe heat illness」「If CWI is unavailable, evaporative cooling is the recommended second-line treatment. … generally half as fast as CWI」https://wms.org/magazine/magazine/1540/Heat-Illness-CPG/default.aspx）；Lipman GS 等 (2019). 同指南 2019 版. https://doi.org/10.1016/j.wem.2018.10.004
Notes: Do not wait for symptoms to “settle down” — heatstroke can progress from dizziness to unconsciousness in just minutes. Never force water into someone who is unconscious; it can cause choking. Opinions differ on where to place ice packs: the Chinese CDC recommends the neck, armpits and groin, whereas the Wilderness Medical Society notes that research shows no distinct cooling benefit from these sites. Their advice is to cover the entire body with ice packs if they’re plentiful, and otherwise apply them to the cheeks, palms and soles. Both sources agree that cold water immersion is the best option when available.