Thermoregulation in the NICU: Part 2 – Making the Move to Crib Life

Last week in Part 1, we explored the why behind thermoregulation—how premature infants lose heat, why they can’t maintain their own temperature, and the equipment we use to keep them warm and safe.

Now in Part 2, we’re moving into the how: how to wean from servo mode to air mode, when it’s time to move to a crib, and how to troubleshoot if temperatures aren’t cooperating. We’ll also talk about one of my favorite parts of the process—partnering with parents so they feel confident when their baby is finally ready for crib life.

Special Considerations for ELBW Infants

Extremely low birth weight infants (<1000g) have the most fragile skin and the highest risk of heat loss. They require humidity for days to weeks, careful positioning, and often servo control long after larger preterm infants have moved on.

• Warmth comes from controlled environment + warm blankets over baby and parent during holding
  These babies are not candidates for early transitions—skin needs to mature and humidity must be off before even thinking about air mode.

From Servo Mode to Air Mode

Air mode means you set the temperature manually. Before making the switch:

• Baby should be off humidity for at least 24–48 hours

• Temperatures should be stable in servo mode (≥97.7°F)

• Skin should look more keratinized, less red and shiny

When switching:

• Set air temp about 1°C below recent servo average

• Keep skin probe on for reference, but don’t base incubator settings on it

• Avoid constant adjustments—let the incubator do the work and reassess every few hours

Weaning to a Crib

This is a milestone moment. While some policies allow a transition at 1600g, most NICUs wait until 1800–2000g with stable weight gain.

Readiness usually includes:

• Stable temp for at least 8–12 hours at 27°C in air mode

• Full feeds with good weight gain

• No recent increases in A/B/D events

When you move to the crib:

• Dress baby in one layer of clothing plus a hat

• Add a sleep sack or two cotton blankets

• Monitor temp every 3–4 hours for the first 24 hours

• Hats are especially helpful during weaning and in the crib—most heat is lost through the head at this stage.

Troubleshooting

Temperature instability during weaning or crib trials can happen. Before turning the heat back up:

• Check skin probe placement (if in servo)

• Consider if a bath, weighing, or extended cares just occurred

• Add a layer or adjust swaddle in the crib

• If temperatures stay low despite interventions, it’s not a failure to go back to the incubator—it’s a sign your baby needs a bit more time.

Partnering with Parents

Parents often underestimate how important temperature is in the NICU. I remind them: “Thermoregulation is a form of life support.” I invite them to help dress their baby for the crib, show them how to check if baby is warm enough, and explain what signs of cold stress look like. When they understand the why, they’re more likely to notice changes at home and keep their baby safe.

Something to Remember

Moving to a crib isn’t just about weight—it’s about maturity, stability, and readiness. A baby who can hold their temperature in a crib is one step closer to going home, but they’ll still need our vigilance, and their parents will need our guidance. Every crib wean is a team effort.