For any person who avidly takes part in any activities which include open water, a wetsuit is an essential piece of equipment.
They make an experience which would, in normal circumstances, be cold and uncomfortable, an enjoyable experience. They allow us to take part in watersports all year round and remove seasonal boundaries that can be caused by the water’s temperature.
We know that wetsuits keep us warm, enabling us to take part in these activities, but how exactly do they work? Today we’ll be answering the question, ‘How does a wetsuit keep you warm?’ by looking at how they work and the effect this has on our body’s natural temperature.
What Is A Wetsuit?
First things first, let’s establish exactly what a wetsuit is. These full-body suits are all too often confused with dry suits because of the similarities in their appearance, but both suits work very differently.
It is a common misconception that you wear a wetsuit to keep you dry while you are out at sea, but this is not true. As their name suggests, wetsuits let water into the suit as part of the heating process.
Wet suits tend to be built of neoprene and provide heat to the wearer while they are taking part in a variety of different watersports and activities.
They were first designed in the 1950s and have evolved since then into the wetsuits we know today. They are available in a variety of different shapes and sizes to fit young children through to fully grown adults.
They also come in different thicknesses which will be better suited to different water temperatures, and can be bought in both full length and cropped designs.
The perfect wetsuit for you will depend on the environment you plan on wearing the suit, the activities you plan on completing in the wetsuit, and the length of time you will be out at sea for.
In order for the wetsuit to work properly, it must be a good fit for your body. Wet suits tend to have a skin-tight design which can make movement on land tricky, to begin with, but allows you to move smoothly once you are in the water.
The fit of the wetsuit is key to its ability to provide you heat, so you must buy one that fits perfectly.
How Does A Wetsuit Work?
Now that we’ve established exactly what a wetsuit is, it’s time to understand how they work and how they can provide us with heat.
The key to the wetsuit’s ability to keep you warm lies in its ability to let in water. A lot of people believe that wearing a wetsuit without getting wet is a way to keep you warm, but the insulation actually comes from the water.
Wetsuits are designed to be tight fitting to your body shape, they stick to your skin but leave just enough room for water to enter.
The very thin gap between your skin and the fabric of the wetsuit will be filled with a very small amount of water. This water becomes trapped between your skin and the wetsuit and will remain there while you are out at sea.
There is such a small volume of water that it allows the natural heat that our body releases to warm the water and provide a layer of insulation. This extra insulation then protects your body temperature against the cold temperatures of the water and keeps you warm while you are completing your watersports.
This warmth protects you from hypothermia, which you would be highly at risk of if you were not wearing a wetsuit.
How Does A Wetsuit Keep You Warm?
The science behind wetsuits is simple. We know that heat tends to gravitate towards colder areas. As we sit in a building at room temperature, our bodies will expel a certain amount of heat.
Similarly, as we go for a walk on a winter day, our bodies will also expel heat which is why we often feel so cold. Wetsuits operate on this basic science, which is added to as water is known to cause heat to be expelled quicker.
In normal circumstances, being exposed to very cold seawater would cause you to also become very cold and your body would then become subject to a condition known as hypothermia.
This occurs when the body becomes so cold that it is unable to reheat itself, causing your organs to struggle and start to shut down.
But wetsuits prevent this from happening due to their perfect design which allows layers of water and material to be used toward your body’s advantage.

We’ve already discussed the layer of water that forms between your body and the wetsuit, but we haven’t discussed the other layers which make the wetsuit operate so well.
If you look at any wetsuit design, you will notice that it is constructed of multiple layers. These are essential for the entrapment of heat within the suit. Just think about cold mornings when you wear multiple layers of clothes to keep you warm, the layers of the wetsuit work in the same way.
Each layer of material will trap a certain amount of air between it, and when these different layers combine they provide excellent insulation against cold weather.
This works perfectly combined with the thick outer layer of the wetsuit. This layer is normally constructed of neoprene which is a thick rubber material, constructed with nitrogen bubbles trapped within it.
Neoprene is a great heat insulator, so when this is combined with the multi-layer build of the wetsuit and the thin layer of water trapped between it and your skin, the different factors together make a supreme heat insulator against the cold temperatures of the sea.
So in short, wetsuits keep you warm through multiple layers of insulation perfectly constructed to keep your body at a warm temperature.
Summary
The idea of a wetsuit seems simple until you strip it all back.
The science is easy to understand, and it is implemented perfectly to ensure your body remains at a good temperature by protecting it from the cold seawater.
The multiple layers of the wetsuit all trap air, the wetsuit itself traps water against your skin and the neoprene outer layer insulates heat within the suit, ensuring you stay warm and allowing you to enjoy all your water activities.