What effect does shivering have on metabolic demand?

Shivering has a significant impact on metabolic demand by increasing it. When the body temperature drops, the body's thermoregulatory mechanisms initiate shivering as a response to help generate heat. This involuntary muscle contraction requires energy, leading to an increase in metabolic activity and oxygen consumption. Specifically, shivering can elevate the basal metabolic rate by 300% to 400% compared to resting levels, which is a substantial increase. The increase in energy expenditure not only helps to raise body temperature but also has implications for patients undergoing procedures requiring cardiopulmonary bypass, as the metabolic demands of the body need to be carefully managed during and after such interventions.

The other choices do not accurately reflect the physiological response to shivering, as shivering clearly serves to enhance metabolic processes and is a critical response for thermoregulation in cold environments.