Very Warm 2.5 Tog Quilted Winter Model Baby Sleep Bag or Sack, Plush Minky Dot for Infants and Toddlers - Medium (10-24 mos) 100% Cotton Inner Lining, Polyester Filling and Outer Shell Imported This is a very warm 2.5 Tog Winter Model baby sleeping bag for room temperatures below 70 F. Minky Dot outer shell and 100% Jersey cotton inner lining. High quality YKK snaps and zippers. WINTER THICKNESS: This is a very warm winter model with a soft polyester filling for more warmth. The recommended nursery temperatures should be between 58F to 69F. A Baby Sleeping Bag surrounds the baby, providing insulation from both below and above, and also a warm pocket of air around the baby.