A critical finding of hyperthermia in a newborn is which of the following?

In the context of hyperthermia in a newborn, tachycardia is recognized as a critical finding because it indicates that the body is experiencing stress due to elevated temperatures. When a newborn's temperature rises, their metabolic demands increase, leading to cardiovascular responses such as an accelerated heart rate. Tachycardia can be detrimental for a newborn, who may already be vulnerable due to immature physiological systems.

It's essential to monitor heart rate closely in newborns with hyperthermia because persistent tachycardia may suggest that the infant is struggling to maintain homeostasis. Early recognition and intervention can prevent further complications that may arise from prolonged hyperthermia, such as dehydration or the failure of multiple organ systems.

The other options may also be associated with hyperthermia but are not as direct. Hypoglycemia, for example, can occur in various situations but is not a primary response to hyperthermia. Shivering is typically not observed in newborns because their ability to shiver is limited, as they rely more on brown fat metabolism to generate heat. Hypotension might occur in severe cases when hyperthermia leads to systemic complications, but it's not a direct or immediate response to the condition itself. Thus, tachycardia stands out as the