Photo courtesy: commons.wikimedia.orgThere may be times when you are out on the water when you want a cold beverage that is, say, homemade. Drinks like lemonade, sweet tea, or any other drink you might mix yourself. A great solution for keeping drinks cold is to keep them in a thermos full of ice. The effectiveness of a thermos is a result of a space of dead air between two containers, usually metal. It is this same air space that makes reflective insulation so effective. What we know now as a thermos was conceived in 1892 by a Scottish scientist by the name of Sir James Dewar and is known as a Vaccum or Dewar Flask. Photo courtesy: commons.wikimedia.org The concept of a thermos is basically the same as the DIY cooler I made for my boat. I had an external container (the bucket) and an internal lining that was reflective on both sides. The important part was the air space between the lining and the bucket. Insulated drink tumblers and coffee mugs operate on the same principle. This air gap is what makes radiant barrier products effective in any installation. radiant barrier products work visit www.ecofoil.com or call 888-349-3645 to speak with one of our product experts.