What happens to the body when in water temperatures below 78 degrees Fahrenheit?

When the body is exposed to water temperatures below 78 degrees Fahrenheit, it undergoes several physiological changes as it responds to the cooler environment. One significant response is a decrease in metabolic and heart rates. This is because colder temperatures can lead to vasoconstriction, where blood vessels narrow, reducing blood flow to the skin and extremities. As a result, the body conserves heat but also experiences a decrease in overall metabolic activity.

This response helps to maintain core body temperature but can also lead to a reduction in physical performance and overall alertness. In contrast, options discussing increased circulation to extremities or improved heat dissipation do not occur under cold conditions, as the body tries to preserve heat rather than dissipate it. Likewise, muscle flexibility typically decreases in cold temperatures, not increases, because muscles tend to be more rigid and less pliable when exposed to cooler environments.