Are you worried about which sleep bag to use and whether your baby will be too hot or cold while sleeping?With Woolino there is no need to worry because exceptionally breathable merino wool naturally regulates baby's body temperature to ensure s/he sleeps comfortably through the night.This luxurious baby sleeping bag will also save you buying lots of different sizes and TOG ratings as it comes in three standard sizes 0-6, 6-18 and 18-36 months and it can be used year-round.• 100% natural: Silky-soft Australian merino wool lining & organic cotton outer. Suitable for room temp. 63-75F (17-24C).• Unlike any other fiber, merino regulates body temperature keeping baby warm when it's cold and cool when it's hot.• Zipper-pull guards to protect child’s skin and discourage child from chewing on the zipper pull. Opens flat for easy dressing.• Machine washable. Can be tumble-dried. Nursery thermometer with dressing guide included.• Beautifully packaged in 100% biodegradable gift box. Woolmark certified merino.• Setting the standard for textile safety, from yarn to finished product, this product bearing the OEKO-TEX STANDARD 100 label (23.HUS.59156, Hohenstein HTTI) has passed safety tests for the presence of harmful substances. Why Merino? A study done by University of Sydney, Australia has found that a better night's sleep is achieved when sleeping in or under wool. Significantly finer than other types of wool, merino is the perfect fiber to have next to child's sensitive skin. It breathes, regulates temperature, manages moisture, is easy to care for, and is durable. It is naturally perfect.