Which pair of hormones works with the kidneys to help avoid dehydration when a person is hot and perspiring?

The pair of hormones that work in conjunction with the kidneys to prevent dehydration during situations involving heat and perspiration is ADH (Antidiuretic Hormone) and Aldosterone.

ADH, produced by the hypothalamus and released by the pituitary gland, plays a crucial role in regulating water balance in the body. When dehydration occurs, such as when a person is hot and perspiring, ADH levels increase, leading the kidneys to reabsorb more water back into the bloodstream, thus reducing urine output and helping to conserve hydration.

Aldosterone, produced by the adrenal glands, also contributes to fluid balance by promoting the reabsorption of sodium in the kidneys. As sodium is reabsorbed, water follows due to osmosis, which further aids in retaining fluids and preventing dehydration.

Together, ADH and Aldosterone effectively maintain fluid balance and electrolytes in the body, especially during conditions where loss of fluids via sweating is significant. This cooperative action helps the body to adapt to heat stress and avoid dehydration.