During viral gastroenteritis, WHO-style oral rehydration therapy uses specific glucose and electrolyte concentrations so the small intestine can absorb sodium even when diarrhea continues. Plain water supports mild thirst but may not replace sodium, potassium, and bicarbonate lost in stool and vomit. For heat exhaustion, move to a cool place, loosen clothing, and hydrate — but call emergency services if mental status changes, skin is hot and dry, or temperature is very high (possible heat stroke).

Reassess hourly early in illness: improving urine frequency and lighter color, tolerating ORS, and stable dizziness are encouraging signs. Worsening scores or new red flags override an earlier mild result.

Older adults may have blunted thirst and lower physiologic reserve — moderate scores warrant lower thresholds for in-person assessment. Pregnancy with hyperemesis or inability to hydrate needs obstetric guidance, not only home ORS. Diabetes can present with vomiting and altered mental status from DKA — this checklist cannot distinguish DKA from simple gastroenteritis. Chronic kidney or heart disease requires individualized fluid plans rather than aggressive self-rehydration from a web score.