Forget everything you think you know about merino wool - it is NOT just for the coldest months of the year. Merino should be used for all newborn babies 365 days of the year for night-time sleeping.
In fact on those warmer nights, it works BETTER than cotton to help regulate temperature and keep your newborn baby cool.
Newborn babies can not regulate temperature for up to the first 12 weeks of life - this means they might be cold even when its hot in the house. So it is really important to use merino against the skin so the merino garment can do the job for them.
Merino will draw the moisture away from your newborn delicate skin when warm and then as the temperature drops (between 3-5am) the merino will push the warmth back into the skin - so they don't wake up because they are cold.
If merino hadn't been invented by nature, you'd be forgiven for thinking it was invented by magic. Unlike man-made fibres, it helps draw moisture away from your baby or toddler's skin and helps them maintain a safe and comfortable temperature in all weather.
The ability to absorb moisture is an important function attribute of Merino fibre, but equally important is its ability to release moisture. In contrast to most synthetic fibres, Merino has the capacity to remove large amounts (up to 35% of its own weight) of moisture from the skin surface before the fibre even begins to feel wet. Merino can prevent the 'clamminess' that can occur in environments with high humidity.
Because infants and children have a higher surface area to mass ratio than adults this makes thermal regulation particularly challenging, and choosing the right garment or sleep system for children becomes extremely important - Merino kids are happy kids!