Final answer:
In a 40.0°C hot tub, sweating will be minimal in cooling effect due to higher temperature and humidity, while increased blood circulation will not effectively dissipate heat, potentially raising the core body temperature.
Step-by-step explanation:
Effect of Heat on Body Temperature
When our bodies become too warm, such as when submerged in a 40.0°C hot tub, we respond with mechanisms like sweating and increased blood circulation to the skin's surface to transfer excess thermal energy away from the core. However, in this case, sweating will have a minimal cooling effect since the water temperature is close to or above the average human body temperature, and high humidity levels above the surface of the hot tub reduce sweat evaporation. Furthermore, increased blood circulation to the surface in such high temperatures will not aid much in cooling the body down, as the environmental temperature is warmer than the body's core temperature; instead, it could potentially lead to an increase in the core temperature if the exposure is prolonged. Consequently, the answer to the question is that thermal energy transfer will increase, but it will not effectively cool down the body, potentially leading to an increase in core temperature: (d) Core temperature will rise.