Baby sleep sacks are recommended by health professionals and used by an increasing number of maternity hospitals, but some are better than others. New scientific research findings released by AgResearch, New Zealand's largest national Crown Research Institute, indicate that baby sleep sacks made from natural wool are better at maintaining a baby's comfort and well-being compared with synthetic fleece sleep sacks.
Scientists have found that babies sleeping in natural merino wool sleep sacks are less likely to overheat and less likely to become damp or chilled compared with babies sleeping in synthetic "polar fleece" baby sleep sacks.
The results of the study indicate that the merino sleep sack is likely the best option for maintaining a baby's thermophysiological comfort and well being in a wide range of conditions.
In particular, the merino sleep sack was found to have moisture vapor absorption over 80 times higher than the polar fleece sleep sack and the merino sleep sack was found to have lower air permeability but the same moisture vapor transmission as the polar fleece sleep sack.