Which symptom is least likely to be associated with dehydration?

Polyuria, which is the excessive production of urine, is least likely to be associated with dehydration because, in cases of dehydration, the body typically tries to conserve water. Dehydration usually leads to a decrease in urine output as the kidneys retain water to maintain adequate fluid levels in the body.

In contrast, the other symptoms like tenting skin turgor indicate a loss of skin elasticity due to reduced fluid levels, dry mucous membranes reflect the lack of moisture present in the body, and an increased heart rate occurs as the body compensates for low blood volume that can result from dehydration. Each of these symptoms highlights the body's response to insufficient hydration, making polyuria an outlier in this context.