A 64-year-old, fair-skinned man in good overall health spent a very hot, humid summer day gardening in his backyard. After several hours in the sun, he began to feel light- headed and confused as he knelt over his vegetable garden. Although earlier, he had been perspiring profusely and appeared flushed, his sweating had eventually stopped. Because he also felt confused and disoriented, he could not recall for how long he had not been perspiring, or even how long it had been since he had taken a drink of water. He called to his wife, who was alarmed to see that his skin had since turned a pale-blue color. She asked her husband to come indoors, but he fainted as soon as he tried to stand. The man was transported to the hospital where he was diagnosed with heatstroke. Outline the changes in cardiovascular status that led to the man fainting.

Faced with excess exposure to the sun, the heat radiated excessively to man and generated a vasodilatation system, which is why the man, when he wanted to move, could not be due to the vasodilation of the upper limb and head, thus generating a fall in blood pressure and consequently generate decompensation.

Vasodilation may have been more noticeable in the upper limb than in the lower limb because of the sum of effects between gravity and heat.

The drop in blood pressure due to vasodilation is what led to a systematic drop in blood pressure, in other cases of a worse situation a hypovolemic shock can be entered.

Explanation:

The heat has a great roll in the vasodilation of both small capillaries and large vessels, in the case of cold the effect is the opposite.

Faced with vasodilation, the tension falls and the cardiac demands are greater, since the heart seeks to compensate for blood pressure and complete irrigation of the upper limb and other organs, which is why it enters a tachycardia state where more cardiac energy is consumed, there is more demand in contraction (higher frequency of contraction, therefore increase in beats per minute)

the answer would be   10%