Which symptoms indicate cold stress in a newborn?

The correct choice highlights symptoms that are commonly associated with cold stress in newborns. Tachycardia (an increased heart rate) occurs as an adaptive response to maintain adequate body temperature when a newborn experiences cold stress. The body attempts to generate more heat through increased metabolic rate, which can lead to respiratory distress as the infant's oxygen demand rises. Hypoglycemia may also develop because the newborn metabolism may shift as energy is expended to generate warmth, leading to a depletion of glucose stores.

In contrast, the other options list symptoms more aligned with different medical conditions. High fever, excessive crying, and dehydration suggest overheating or illness rather than cold stress. Meanwhile, symptoms like skin rash and blue extremities typically indicate issues related to poor circulation or other more severe conditions, rather than cold stress specifically. Vomiting, diarrhea, and poor feeding are symptoms generally associated with gastrointestinal disturbances, which are not characteristic of cold stress.