Infants Are at a Higher Risk of Dehydration Than Adults

Infants have a higher risk of dehydration states because they haven't learned their thirst reflex yet. Infants are losing more fluid proportionally than an adult would due to greater surface area to volume ratio. Same with the elderly. They've kind of decreased in their thirst. That's not depleted, but it's just the efficiency of that thirst reflex in the elderly's diminishing.