A sleep sack has closed legs (or an opening at the bottom) and keeps the legs together for sleep. A sleepsuit has separated legs — the baby can stand, walk, and crawl in it. The sleepsuit is the wearable blanket for walking toddlers who still need TOG warmth at night.
When the baby is walking confidently in the crib, usually 12–15 months. The closed-leg sleep bag becomes a trip hazard at that point. Some families switch earlier if the baby protests the closed-leg format.
At 1.0 TOG, yes — in a 69–75°F nursery, which is the most common US nursery temperature. For warmer summer nights above 75°F, switch to lighter pajamas alone. For cold winter rooms below 68°F, layer a long-sleeve bodysuit underneath.
Closed sleeves are how you overheat a baby overnight. The warmth math sits in the body of the suit, not the limbs. Sleeveless construction also makes it easier to dress a sleepy toddler at 7:30 p.m.
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Loulou Lollipop is a 2015-founded, Canadian-based, women-owned and AAPI-owned direct-to-consumer brand making sustainable, design-led baby and children's products — including sleep bags, muslin swaddles, silicone feeding items, and clothing — for parents who prioritize safety, sustainability, and aesthetics.