Airtabs™ are made of Styrosun® injection molded plastic. Thousands of Airtabs have now been in service for several years in Australia, South Africa, Europe and in North America from Florida to Alaska (winter & summer operations) There have been no reported temperature extreme related material failure issues in our history as Styrosun® has additional UV protection and is designed to withstand these temperature extremes. However, we would not recommend hitting one with a hammer at minus 40.