Halo SleepSack Wearable Cotton Blanket - Back is BestDesigned by a parent who lost an infant to SIDS (Sudden Infant Death Syndrome), and now being used in hospital nurseries nationwide, the HALO SleepSack wearable blanket replaces loose bedding in the crib that can cover your baby"s face and interfere with breathing. It"s the only product that carries the gold seals from First Candle/SIDS Alliance and the Canadian Foundation for the Study of Infant Deaths.