. It's ideal when outdoor temperatures range between 5° and 5°.product details • thermal grade 3 medium warmth, ideal for winter. • elasticated waist. Fabric content and care advice • 50% acrylic, 50% polyester • please refer to the care instructions on the product label damart has been keeping france and other countries warm for 65 years now thanks to its innovative thermolactyl fibre, that's gone on to achieve cult status. Often imitated, but never matched! So, here's a shout out to all those who feel the cold and who like to look good thermolactyl is the new cool!