Integumentary System and Thermoregulation (3B) Practice Test

In an environmental chamber study, healthy volunteers rested for 20 minutes at 24°C and then were exposed to 40°C air (20% humidity) for 15 minutes while core temperature remained stable (≤0.1°C change). Infrared thermography showed increased skin temperature over the forearm, and laser Doppler flowmetry showed increased cutaneous blood flow at the same site. The central thermoregulatory principle under investigation is cutaneous vasodilation. Based on the scenario, which outcome is most consistent with thermoregulation?

In an environmental chamber study, healthy adults sat at rest for 30 minutes at 24°C, then were exposed to 40°C dry air for 20 minutes. Core temperature increased slightly (≈0.3°C), while skin temperature rose rapidly, and laser Doppler measurements showed increased cutaneous blood flow on the forearm. The central thermoregulatory principle under investigation is cutaneous vasodilation to enhance heat transfer from core to skin. Based on this scenario, which outcome is most consistent with thermoregulation during the 40°C exposure?