Short answer: dress the baby for the room they're sleeping in, not the weather outside — and in Florida those are two different climates. The American Academy of Pediatrics advises dressing an infant in no more than one additional layer than an adult would wear to be comfortable in that same environment, and warns against overheating and head covering. In a house cooled to the high 60s or low 70s, that usually means one light sleeper, sometimes with a wearable blanket over it. Outside on the same afternoon it means much less.
Why is Florida a special case?
Because the air conditioning does the deciding, not the season.
A Miami summer day is hot and humid — NOAA's climate normals put the average July high near 90 °F. The bedroom the baby sleeps in that night may be twenty degrees cooler. Parents dress for the day they experienced and then wonder why the baby wakes at 4 a.m. with cold hands, or the reverse: they dress for "summer" and the vent blows straight over the crib all night.
The useful habit is to stop thinking about the month and start thinking about the room. Put a cheap thermometer where the crib is — not in the hallway — and dress to that number.
What does the AAP actually say about temperature and layers?
Three things, and they're worth quoting carefully because this is the part where the internet invents rules.
- The AAP's 2022 policy statement Sleep-Related Infant Deaths: Updated 2022 Recommendations for Reducing Infant Deaths in the Sleep Environment states that there is not enough evidence to recommend a specific room temperature for infant sleep. There is no official "correct" nursery temperature. Anyone who gives you one is giving you an opinion.
- The AAP advises dressing the infant in no more than one layer more than an adult would wear to be comfortable in that environment, and evaluating the infant for signs of overheating such as sweating or the chest feeling hot to the touch.
- The AAP advises avoiding overheating and head covering during sleep.
That "one more layer than you" rule is the one to carry around, because it travels. It works in a cold guest room in December and in an over-air-conditioned condo in August, and it doesn't require you to memorize a chart.
So what does the baby wear at each room temperature?
There is no official chart, so here is how the AAP rule applies in practice, with the honest label attached: this is the "one more layer than you" rule worked through, not a standard.
| Room feels… | What an adult wears to be comfortable | Baby: one layer more |
|---|---|---|
| Cool (AC running hard, you'd want a light sweater) | Long sleeves | Long-sleeve footed sleeper, plus a wearable blanket |
| Comfortable (you'd sleep in a t-shirt and a light sheet) | T-shirt | Long-sleeve footed sleeper, or a short-sleeve sleeper plus a wearable blanket |
| Warm (you'd sleep with no cover) | T-shirt, no cover | Short-sleeve one-piece or a bodysuit |
| Hot (no AC, humid night) | As little as possible | A single light layer — a short-sleeve bodysuit. Do not add a blanket. |
Feel the back of the neck or the chest to check, not the hands or feet. Babies' extremities run cool and tell you almost nothing.
What about blankets, sleep sacks and swaddles?
This is safety territory, so it stays close to the source.
The AAP's 2022 recommendations are that infants sleep on their back, on a firm, flat, non-inclined surface, in a crib, bassinet, portable crib or play yard with a fitted sheet, and that soft objects and loose bedding — including pillows, quilts, comforters, blankets and bumper pads — be kept out of the sleep area. Where extra warmth is needed, sleep clothing such as a wearable blanket is preferable to a loose blanket.
The 2022 statement also advises against weighted blankets, weighted swaddles and weighted objects on or near a sleeping infant.
On swaddling: the AAP notes that swaddling should stop when the infant shows any sign of attempting to roll, and that if swaddling is used, the infant must always be placed on their back and the swaddle must not be so tight that it restricts chest expansion or hip movement.
None of that is JOWI's opinion. It's the policy statement, and the link is at the bottom.
What about the car, the stroller and the drive home?
Florida's practical problem isn't only the bedroom — it's the twenty minutes in a car that has been sitting in a parking lot.
Dress in layers you can remove in the back seat with one hand, and take the extra layer off before the drive rather than after. Anything that covers the head and face in a stroller or car seat should be removed once you're inside, because the AAP's warning about head covering applies wherever the baby sleeps — and babies fall asleep in strollers.
Does the fabric matter in Florida heat?
Less than the amount of it.
A single light layer of any breathable knit beats a heavier layer of a fabric with a better story. Fiber marketing in this category leans hard on words like "cooling" and "temperature regulating"; what actually governs how warm a baby gets is the number of layers, how much of the body they cover and what the room is doing.
That said, some real differences exist, and they're worth knowing when you're choosing between a bamboo viscose knit and cotton — we go through them in bamboo, cotton or a blend.
A short Florida routine that works
- Put a thermometer at crib height and read it at bedtime, not in the afternoon.
- Ask yourself what you would wear to sleep comfortably in that room. Give the baby one layer more.
- Keep the crib empty: firm flat surface, fitted sheet, nothing else.
- If more warmth is needed, add a wearable blanket, not a loose one.
- Check the back of the neck once during a night feed. Sweaty means one layer too many.
- Aim the AC vent away from the crib, or crack the door instead of dropping the thermostat.
If any of this bumps into your baby's specific health situation — prematurity, a heart or lung condition, a fever — ask your pediatrician. The guidance above is for healthy infants and it is general.
Once you've settled what the baby sleeps in, the next practical question is usually how many of them you need. That's how many pajamas a baby actually needs per size.
Sources
- American Academy of Pediatrics, Sleep-Related Infant Deaths: Updated 2022 Recommendations for Reducing Infant Deaths in the Sleep Environment, Pediatrics, Vol. 150, No. 1, July 2022.
- American Academy of Pediatrics, HealthyChildren.org, How to Keep Your Sleeping Baby Safe: AAP Policy Explained — healthychildren.org
- NOAA National Centers for Environmental Information, U.S. Climate Normals (1991–2020), Miami, Florida — ncei.noaa.gov