Which environmental factor can artificially elevate BP readings?

• A. Cold environment
• B. Warm environment
• C. Low humidity
• D. Bright light

Answer: (A)

Cold exposure elevates BP readings because the body's response to cold is to constrict blood vessels and ramp up sympathetic activity. When vessels in the skin and extremities constrict, peripheral vascular resistance goes up, so the heart has to pump harder to move blood through the narrow vessels. That increased resistance shows up as higher systolic (and often diastolic) pressures on the cuff. In a warm environment, vessels dilate, which tends to lower the resistance and can yield lower readings. The effects of low humidity or bright light aren’t as direct or reliable in raising BP to the same degree. For accurate measurements, keep the room comfortably warm (around 20–22°C), let the patient rest, and ensure proper technique so temperature-related effects don’t skew the result.