Hocosa's 100% Organic Merino Wool Shirt is a natural for babies as a base layer. Warmth and moisture-regulating, it keeps baby warm in the cooler months and cooler in the warmer months. It absorbs up to one third of its own weight in moisture and depending on external conditions, is able to return it to the environment. Pair the shirt with the striped long johns. Wash by hand or machine washable on gentle cycle in warm water.