Which condition would place a patient at the highest risk for heat intolerance during aquatic physical therapy?

• A. Hypothyroidism
• B. Hypoparathyroidism
• C. Hyperthyroidism
• D. Hyperparathyroidism

Answer: (C)

Heat intolerance during exercise hinges on how much heat your body produces versus how well you can dissipate it. When thyroid hormone levels are high, the body's metabolism speeds up, so more heat is generated even at rest and during activity. In aquatic therapy, the water helps cool the body, but the extra heat produced in hyperthyroidism can overwhelm that cooling, increasing the risk of overheating, rapid heart rate, dizziness, and fatigue during the session. That’s why this condition carries the highest risk for heat intolerance among the options.

Lower thyroid activity, as in hypothyroidism, slows metabolism and reduces heat production, which makes overheating less likely. Parathyroid disorders—whether too much or too little hormone—don’t directly cause increased heat production or thermoregulatory failure, so they’re not typically linked to heat intolerance in the same way.