Usually 2500-3000mL of water per day is the most appropriate amount for adults, but there is an exception for such adults. If an adult becomes dehydrated and suffers from heat stroke or aura of heat stroke in the summer, such as heat cramps, heat exhaustion and pyrexia, it is necessary to drink more than 1000-1500mL of drinking water on top of the above. In case of poor feeding or dehydration, such as acute gastroenteritis with increased diarrhea and vomiting, it is also necessary to add about 1000mL of drinking water on top of the above mentioned water intake to avoid dehydration shock or severe water loss and ionic disorders.