Final answer:
The EP-C can expect an increased heart rate during exercise in the heat compared to a thermoneutral environment, because of the body's effort to dissipate heat through sweating and increased blood flow to the skin. Hydration is crucial, but the HR increase is a general response to heat.
Step-by-step explanation:
When considering the heart rate (HR) response at a given workload during exercise in hot environments compared to thermoneutral environments, one should expect an increased HR in the heat.
This happens because the body needs to work harder to dissipate the extra thermal load. In a hot environment, as internal body temperature rises, the body's responses include sweating and an increased flow of blood to the skin to facilitate heat loss. However, these mechanisms require the heart to pump more blood, thus increasing the HR. It's also critical to understand that sweating is less effective in high humidity, as the air is saturated with water and sweat does not evaporate as readily, potentially leading to dangerously high internal body temperatures.
Adequate hydration is essential for effective thermoregulation during exercise in the heat. The body relies on the extracellular fluid to produce sweat, and fluid intake is necessary to balance the loss through sweating. Hence, while hydration status can influence HR response, the general expectation in the heat is an increased HR compared to a thermoneutral environment, regardless of hydration.