A baby’s first cry is a sound like none other. We know that infants must learn to breathe on their own, and fast. And they must also survive being pushed from the perfection of their mothers’ warmth.

To be expelled, soaking wet, not wearing a stitch, suddenly exposed to room temperature, or worse—what a shock.

Here’s the problem: The newborn brain is too immature to maintain body temperature. Even a healthy, full-term infant has few defenses against cold stress.

That’s why delivery room nurses slip stockinette caps onto newborn heads. The scalp has a relatively large surface area from which heat can be lost and if an infant’s temperature dips too low for too long, cold injury can trigger a chain reaction that ends in death.