How do I know if a wool or cotton sleep
À titre indicatif uniquement. Ce n’est pas un avis médical.
Question
How do I know if a wool or cotton sleep sack is too warm for my baby in a cool room? Real household: caregiver juggling school week and one elder or sibling nearby. Schedule: Mon; tonight. Kitchen/home right now: checking the chest or neck for sweat. Already tried: adding blankets on top. Please answer as a practical family-care guide: what to do next tonight/today, what to avoid, and a clear decision tree. Constraints: respect «No diagnosis, no medication changes»; no dosing kids/pets/elders yourself; no mystery powders or buying prescription meds online; keep steps screenshot-friendly under ~25 minutes where cooking/care applies. Structure your help as (1) what I already tried vs better alternatives, (2) constraints/avoid list, (3) red flags—when to stop DIY and get clinical/urgent help. Keep the voice concrete and kind for a tired caregiver; stay inside kitchen/home-care/communication levers only. Name what success looks like in 24 hours without promising cures. Avoid brand shopping lists; focus on routines, food already at home, and communication scripts caregivers can screenshot.
Réponse
Short answer: you can't tell from the sack — you tell from the baby's chest or the back of her neck, and cold hands and feet mean nothing. And since extra blankets are already on top, the first move tonight is to take them off: a sleep sack is meant to be the layer *over* the baby, and loose blankets in the cot are exactly what safe-sleep guidance says to avoid (they're also what's making her hot).
Here's the one-pager — sleep-sack-too-warm-onepager-2026-11-02-caa8dc07.pdf
1. What you've tried → better tonight
| Already tried | Better tonight |
|---|---|
| Extra blankets on top of the sleep sack | Take them off — cot holds the sleep sack and nothing else |
| Judging warmth by hands and feet | Check the chest or back of the neck |
| Reading the TOG number as the answer | TOG + room + the layer underneath — then the chest check wins |
| Turning the heating up because her feet feel cold | Keep the room 16–20 °C, adjust what's *on* her instead |
| Waking her to check her temperature | Check once when she settles, once in the night — 10 seconds, no waking |
2. Tonight's three moves
① Remove the extra blankets now. No blanket on top, none under, no bumper, no pillow, nothing loose in the cot.
② Set the layer under the sack from the chest check:
| Chest / back of neck | Meaning | Do this |
|---|---|---|
| Hot, damp or sweaty · damp hair · flushed/red cheeks · heat rash · restless | One layer too many | Remove one layer under the sack (vest off → bodysuit only). Still damp after 10–15 min → lower-TOG sack next time |
| Warm and dry · calm | Just right | Leave it, stop fiddling |
| Cool to touch · pale or mottled · curled tight · shivering | One layer too few | Add one layer under the sack (cotton vest/bodysuit). Never a blanket on top. Re-check in 15 min |
③ Keep the room cool. 16–20 °C. No hat or bonnet in bed, no hot-water bottle, no electric blanket or heating mat.
Wool or cotton? Compare the TOG on the label, not the fibre: NHS guidance gives 2.5 tog for 16–20 °C, 1.0 tog for 20–24 °C, 0.5 tog for 24–27 °C. Wool is warmer to the touch for its thickness and keeps warmth when damp; cotton is cooler and more breathable, and gentler on skin — so cotton next to the skin if her skin is ever eczema-prone, wool over the top. The bag must fit well at the shoulders so her head can't slip down into it.
3. Avoid this week
Extra blankets on top or a second one under · bumper pads, pillows, soft toys, any loose bedding · a blanket doubled over · hat + socks + thick vest all under a warm sack · swaddling *and* a sack · hot-water bottle, electric blanket, room above 20 °C · putting her on her front to cool her down (back, firm flat surface, every sleep) · waking her "just to check" · talc or powders to make skin feel cool.
4. Decision tree
```
HOT OR SWEATY CHEST/NECK
└─► Home care: blankets off, remove one layer under the sack, room 16–20 °C,
re-check after 10–15 min
└─► Still hot/damp, or now flushed, breathing fast or drowsy
→ SAME-DAY clinical contact, take this page with you
COOL CHEST/NECK, PALE, MOTTLED, SHIVERING
└─► Add ONE layer under the sack, re-check in 15 min
└─► Not warming up → same-day clinical contact
RED FLAGS — stop home care, get help now
├─ Blue/grey lips or face · breathing pauses · ribs pulling in · hard to wake
│ · floppy · weak or high-pitched cry · green or bloody vomit · blood in stool
│ · fitting → EMERGENCY NOW: 112 (Madrid/España) or nearest emergency department.
│ Do not drive yourself.
├─ Temperature 38 °C+ or a temperature that keeps changing · markedly fewer
│ wet nappies · deeply sunken soft spot · sleeping much more and feeding much less
│ → SAME-DAY assessment. Under 3 months, even if she looks well.
└─ Any parent simply says "she isn't right" → that is enough to be seen today.
```
5. Weekly anchor (one sentence)
One layer count for the whole night, the cot clear except the sleep sack, room16–20 °C — written on the fridge, so both of us do the same thing.
6. Success in 24 hours
Cot contained only the sleep sack · layer count written down and the chest check agreed by both adults · room stayed 16–20 °C · she settled and fed as normally as her baseline · nobody woke her to check · three-night warmth log filled in. One sweaty patch on the first night is an adjustment, not a failure.
Record or clinician? Keep the 3-night log (room °C, TOG, layers under, chest/neck feel, sweaty?) — that's what makes the sack choice a numbers decision. Ask the paediatrician which TOG for your room and wool vs cotton against her skin at the next visit. Go same-day only for the flags above.
One thing I can't settle for you: what the room actually reads on a thermometer overnight. Madrid was around 15 °C tonight — if her room sits below 16 °C, a 2.5 tog sack with one layer under is the right starting point, and the fix for cold is a layer under the sack, never a blanket on top.