Describe the typical cardiovascular response to heat exposure at rest.

Describe the typical cardiovascular response to heat exposure at rest.

• A. Dehydration only
• B. Skin vasodilation to increase heat loss, increased heart rate and cardiac output, with possible plasma volume shifts
• C. Decreased ventilation
• D. Decreased skin temperature

Answer: (B)

When heat exposure occurs at rest, the body prioritizes getting heat from the core to the skin. The main cardiovascular change is cutaneous vasodilation, which increases skin blood flow to promote heat loss. To support this greater skin perfusion and ongoing sweating, heart rate rises and cardiac output increases. Sweating can reduce plasma volume, shifting fluid out of the intravascular space and potentially lowering venous return, which may limit stroke volume if dehydration progresses. So the typical response is more skin blood flow with higher heart rate and cardiac output, and possible plasma volume shifts. Dehydration is a consequence rather than the primary response, ventilation tends to increase, and skin temperature rises with increased skin blood flow rather than decreasing.

When heat exposure occurs at rest, the body prioritizes getting heat from the core to the skin. The main cardiovascular change is cutaneous vasodilation, which increases skin blood flow to promote heat loss. To support this greater skin perfusion and ongoing sweating, heart rate rises and cardiac output increases. Sweating can reduce plasma volume, shifting fluid out of the intravascular space and potentially lowering venous return, which may limit stroke volume if dehydration progresses. So the typical response is more skin blood flow with higher heart rate and cardiac output, and possible plasma volume shifts. Dehydration is a consequence rather than the primary response, ventilation tends to increase, and skin temperature rises with increased skin blood flow rather than decreasing.