For people suffering from heatstroke, as long as they remain conscious, they should drink small amounts of cool, lightly salted water or sports drinks at frequent intervals — never gulp down large quantities. Alcohol and sugary drinks must be avoided

Cost: No cost involved. A bottle of sports drink costs just a few yuan.
In plain terms: Only conscious individuals should drink. Consume cool, lightly salted water or sports drinks in small portions, about 500–1000 ml per hour. Do not drink too much at once; vomiting can cause liquid to enter the airways, which is far more dangerous than heatstroke itself. Alcohol and sugary drinks must be avoided, as they cause further fluid loss. Applying cool water to the skin or using ice packs on the neck, armpits, and inner thighs is recommended — cooling should always come before rehydration. Never give anything to drink to someone who is unconscious or speaking incoherently.
Benefit: The Chinese CDC published the “Guidelines on Prevention and Emergency Treatment of Heatstroke (2014),” which states: “Consume at least 2–4 cups of cool water per hour (500–1000 ml), ensuring the temperature is not excessively high; drinking should be done in small amounts at frequent intervals.” It also advises: “Avoid beverages containing alcohol or large amounts of sugar, as these lead to further fluid loss. Do not consume overly cold drinks.” For heatstroke specifically, the guidelines explicitly warn: “Do not give the patient any water to drink.” NIOSH in the U.S. recommends encouraging “small, frequent sips of cool water” for heat exhaustion, and for heat cramps, suggests sports drinks with sugar and electrolytes every 15–20 minutes — “do not use salt tablets.”
Evidence grade: B
Sources:中国疾病预防控制中心职业卫生与中毒控制所 (2014). 公众高温中暑预防与紧急处理指南（2014 版）. https://niohp.chinacdc.cn/sndt/201405/t20140530_97623.htm ; US CDC/NIOSH. Heat-Related Illnesses. https://www.cdc.gov/niosh/heat-stress/about/illnesses.html
Notes: After heavy sweating, drinking plain water alone dilutes blood sodium levels, so a bit of salt must be added to the water. Gulping down large amounts at once often leads to vomiting, which can be fatal if liquid enters the airways. The 2014 Chinese CDC guideline advises against “very cold drinks” to prevent stomach cramps, though no quantitative evidence supports this restriction; it should not be interpreted as “no cold drinks at all.” In item 22, several cooling methods are described: wiping the body with cool water, immersing in cold water, and applying ice packs to the neck, armpits, and inner thighs — all of which are officially recommended first-line measures. These are meant for external application, not ingestion, and cooling must always precede rehydration. Never give anything to drink to anyone who is unconscious or speaking unclearly.