You Asked:

How does a wet suit work? — Dori, Mckinney, Texas

Marshall Brain Answers:

When you are walking on a cold winter day, you wear a down coat. The coat provides an inch or so of still air around your body that acts as insulation.

A wet suit works the same way in cold water. It provides a layer of waterproof flexible foam (neoprene) that acts as insulation and keeps out most of the water. Some water does get in at your neck, wrists and ankles. This water warms quickly to body temperature and provides a little more insulation. However, it is essential that your wet suit fits tightly so the movement of water through the suit is minimized. If the suit is too big, it is “drafty” and the cold water that moves through the suit chills you.

Could you wear a wet suit on land to take a walk? You could, except for one problem. The foam is waterproof, so it traps sweat inside the suit. It might not be the most comfortable thing to walk around in.

This video shows you several things to keep in mind when looking at wet suits:

The alternative to a wet suit it a dry suit. It is made from thick, waterproof material, but it is sealed tightly at the wrists and neck to keep all water out. Here’s a nice introduction:

For more info see:
- How long can someone survive in frigid water?
- Why do we breathe more rapidly when we get in very cold water?
- Swimming under ice
- How Scuba Works