For those extremely cold days you may need much more coverage than just over the mouth and nose.
The Smartwool Merino 250 balaclava gives you full head coverage while remaining breathable. The eye area is left completely clear of obstruction, but if some runners opt to wear sunglasses these will mist over unless the mask is pulled below the nose.
Being made from wool you could be forgiven for thinking that the airflow wouldn’t be great, but the Smartwool Merino 250 has excellent air circulation, perfect for heavy exercise.
We are huge advocates for anything merino wool to be donned during winter hikes. In fact, it’s safer, especially if you get it wet along the way. Moreover, merino wool has thermoregulating properties where it holds heat when needed, but keeps the skin cool when its warm out, like magic.