In high heat, if there is dizziness, nausea, no sweating or confusion, move to a cool place at once, take off clothing and pour water to cool down, don't give water to someone who isn't fully conscious, and call 120 (China's ambulance number)

In a real emergency, call 911 first, then read this.

Cost

Free.

What you get

The U.S. National Weather Service: heat stroke is a "serious medical emergency." Its signs are a body temperature above 103°F (39.4°C), confusion, slurred speech, and hot, red skin. The handling is to call for emergency help at once, move to a cool place, cool with cold water and wet cloths, and "give no fluids." The signs of heat exhaustion are heavy sweating, weakness, cold clammy skin, and a fast, weak pulse, and the handling is to move to a cool place, loosen clothing and sip water; get medical care if there is vomiting, if it gets worse, or if it does not ease within 1 hour. A notice from the Yunnan Provincial Disease Control Administration (云南省疾控局): move at once to a cool, ventilated place, cool with a cold wet towel, give salted drinks to those who are conscious, and call the emergency number at once for serious symptoms; severe heat stroke has a "very high death rate." A notice from the Chinese Center for Disease Control and Prevention: cool first, transport after, and cool within the "golden half hour" after the person loses consciousness. Where possible, young and middle-aged people with no underlying illness can be cooled quickly by soaking in cold water, and older people and those with underlying illness can be sprayed with water and cooled by evaporation. The Wilderness Medical Society's heat illness guideline, updated in 2024, says cold-water immersion is the most important way to treat severe heat stroke and cools fastest. If there is no ice water, use the coldest water at hand, and if you can't immerse the person, spray with water and fan, which works at about half the speed of immersion. The U.S. National Institute for Occupational Safety and Health (NIOSH) says that during heat stroke body temperature can rise above 106°F (about 41 ℃) within 10 to 15 minutes. Among the symptoms it lists are "hot, dry skin, or heavy sweating." The Chinese CDC's 2014 heat illness guide lists, as signs of heat stroke, "skin that is red, hot and dry with no sweating," and its handling instructions say "do not give the patient water," and if the patient vomits, turn them onto their side to keep the airway clear

Notes

Don't wait to "rest a bit," because in heat stroke the body temperature can rise above 41 ℃ in a dozen or so minutes. Heat stroke may come with no sweating, or with heavy sweating; NIOSH lists both, so don't let it pass just because the person is still sweating. Don't force water into someone who is not fully conscious, and if they vomit, lay them on their side. The two sides differ on where to put ice packs. The Chinese Center for Disease Control says to apply them at the neck, armpits and groin, while the Wilderness Medical Society says research shows no cooling effect from applying them to these spots. Its advice is, if only ice packs are available, cover the whole body, and if there are not enough, put the rest on the cheeks, palms and soles. Both say to use cold-water immersion if it is available.

Evidence grade

B : Supported by research but without a precise number, or based on small or single studies.

Sources

1. US National Weather Service. Heat Related Illnesses. https://www.weather.gov/safety/heat-illness
2. Yunnan Provincial Disease Control and Prevention Administration (2026). If You Have These Symptoms, You May Have Heatstroke [in Chinese]. https://ynsjkj.yn.gov.cn/html/2026/jikongkepu_0719/2606.html
3. Chinese Center for Disease Control and Prevention. In Hot Weather, China CDC Reminds You to Guard Against Heatstroke [in Chinese]: "If conditions allow, cold-water immersion can be used to cool young and middle-aged adults without underlying disease quickly. Older people and patients with underlying disease can be cooled by spraying water on the skin so that it evaporates. Cooling should follow the principle of 'cool first, transport later.'" https://www.chinacdc.cn/jkkp/ggws/hjyssj/202409/t20240906_296985.html
4. National Health Commission (2010). Key Points on Preventing Heatstroke in High Temperatures [in Chinese]. https://www.nhc.gov.cn/wjw/jbyfykz/201007/1edb19b7dd4e4bdf8da5ea45f4a64e23.shtml
5. Eifling KP et al. (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 (the site of the full text refuses automated retrieval, so the specific recommendations were checked against the update summary on the Wilderness Medical Society website: "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)
6. Lipman GS et al. (2019). The same guideline, 2019 edition. https://doi.org/10.1016/j.wem.2018.10.004
7. US CDC/NIOSH. Heat-related Illnesses: "When heat stroke occurs, the body temperature can rise to 106°F or higher within 10 to 15 minutes" "Hot, dry skin or profuse sweating". https://www.cdc.gov/niosh/heat-stress/about/illnesses.html
8. National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention (2014). Guide to Public Prevention and Emergency Handling of Heatstroke in High Temperatures (2014 edition) [in Chinese]. https://niohp.chinacdc.cn/sndt/201405/t20140530_97623.htm

Translated from the Chinese original. Original book, section 13, tip 22. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer