Water conducts heat from your body 25 times more efficiently than air, so if you’re to spend any length of time in water colder than 32ºc you will require some extra insulation to prevent you becoming uncomfortably cold or suffering from hypothermia . Bring on the wetsuit.
Most wetsuits are made from neoprene or a combination of neoprene and other materials. Wetsuit neoprene contains tiny nitrogen gas bubbles. Nitrogen gas has very low heat conductivity. Your wetsuit works by trapping a small amount of water next to your skin. The nitrogen gas bubbles, in the material, reduce the amount of heat loss from the trapped water, keeping you comfortably warm for longer.
The thicker the neoprene, the warmer the wetsuit will be. However, thicker wetsuits are usually less flexible.
You’ll notice that when you first get into the water in your wetsuit that the water will slowly seep in, and initially it will feel cold. Within a few minutes that water will heat up to match your body temperature, and keep you warm. Some people pee in their wetsuits once they get into cold water to speed up the warming process.
