When planning a cold water swim, think about the kit you need both in the water and pre and post your swim - lists of both in-water and topside kit is provided opposite. Do not hesitate to ask if you need advice on cold water specific equipment - many items can be found in our onsite shop. A full range of hot drinks and food are also available onsite.

When choosing a wetsuit for cold water swimming, the most important consideration is fit. How well a wetsuit fits is vitally important as an ill-fitting suit with restrict your movement and allow cold water from the lake to flush through it, reducing any thermal benefit you gain by wearing a wetsuit!

We recommend a full suit so that as much of your body (including arms and legs) is protected by a layer of thermal insulation. A decent swim wetsuit will vastly improve your cold water swimming experience and will prove to be a worthwhile investment!

Cold water shock can be experienced at any time in the year when you first get into relatively cold water. This initial reaction to cold water can lead you to stop breathing or cause rapid hyperventilation - in extreme cases, it could even trigger a cardiac arrest. As suggested above, appropriate and progressive immersion with controlled breathing is the best way to prevent or limit 'cold water' shock. DO NOT DIVE IN as this causes rapid cold water shock.

After chill occurs when the body's core temperature continues to drop despite the swimmer exiting the water and in the relative warm. Prolonged cold water exposure and/or rapid re-warming such as having a hot shower can cause the blood to flush to the peripheral blood vessels and away from the body's core. This can lead to dizziness, nausea, fainting and ultimately severe hypothermia/cardiac arrest. Once out of the water, gradually re-warm following the advice opposite and make sure that you feel ok before you drive.

Exposure to cold environments such as cold water, low air temperatures and wind chill can lead to the rapid onset of hypothermia. Whilst the colder the conditions the body is exposed to the more rapid the onset, factors such as age, gender, body type and acclimatization will influence how quickly you might develop hypothermia and its severity. There is therefore no reliable method of predicting the rate of onset in even the most seasoned swimmers.

When you are swimming in water colder than you, your body initiates a process to protect your vital organs. Blood vessels shunt (moving blood to where it's needed) the warm blood away from your skin and limbs towards your vital organs by reducing the blood flow to your extremities. This allows more oxygen to be delivered where it's needed the most. Your body will be working hard to maintain your core at its normal temperature. This process is called peripheral vasoconstriction. It's the body's way of protecting against hypothermia.

This process starts to reverse when you get out of the cold water. Your body begins to send the warm blood from the core back to the skin to warm up again. The problem is that it also cools the blood as it does so, as it's now mixing the warm blood with the cooler blood, and then re-circulates the cool blood back to the core, meaning that your temperature will drop further.

This is known as the 'after-drop'. This doesn't happen immediately, and when you exit the water you'll probably feel great for a short time. This delay occurs because your cooler blood hasn't reached your core straight away. Within a short space of time, however, you will begin to shiver. Shivering is one of our body's immediate reactions to generate heat. Shivering makes your muscles contract and relax quickly to produce heat to raise your body temperature.

The symptoms of hypothermia can onset at different rates and you may not always be aware of them developing as hypothermia can affect, amongst other things, your cognitive ability - ie. your ability to think clearly and make intelligent decisions. Your brain is very sensitive to the cold and electrical activity rapidly slows down in response to it, so your ability to make decisions and react becomes impaired.

Think you may be suffering from hypothermia?
If you suspect that either you or your swim buddy is suffering from the onset of hypothermia after exiting the water, that person should immediately dry off and wrap themselves in towels and layers of warm clothing and a hat, focusing particularly on the extremeties. A severely hypothermic swimmer may need medical attention so always inform a member of our staff immediately.

• Make sure that you have suitable kit - not just for before and during your swim, but also for your post swim recovery (layer like an onion skin rather than one thick layer such as a change robe).
• Make sure that you have eaten something a while before you swim, not just for energy but also to increase your metabolic core temperature.
• Have hot drink and food available or money to purchase some from the on-site catering to aid your post swim recovery.
• Pack a hot water bottle in your kit bag, your post swim clothes will be warm, and you will have something to hug afterwards.

• As the temperature of the water drops, reduce the duration of your swim and your exposure to cold water.
• Set realistic goals for your first swim back - the water temp is still in single figures until May, so a short swim and re-acclimatisation is fine.
• If you have been swimming in other locations, please help us to protect our ecology - especially our native whiteclawed crayfish - by thoroughly washing and rinsing your swim kit.

• Be positive and progressive entering the water - wash your face, splash water on your skin, flush your wetsuit and slip into the water focusing on relaxed long breathes out rather than shouting or gasping
• Take your time to settle your breathing with slow deliberate head up strokes, use the three-breath test before swimming at any speed
• If you are new to cold water swimming please swim around the 300 metre loop not the full 750 metre course. From 1st December to 30th March we open the short 140m winter loop, which is locally known as 'The crack and back'. This is the shortest distance that you can swim at Vobster during these months.
• Swim within your own limits, listen to your body and get out before you get too cold as your core temperature can continue to drop significantly after you exit the water
• Do not compete with others, if you are cold get out and gradually re-warm
• Recognise the signs and symptoms of core temp drop and hypothermia

• Remove all cold wet clothing as quickly as possible and either get dressed quickly and warmly or cover yourself with warm blankets. Immediately after swimming you may feel great as the cooled blood has not yet returned to your core.
• Don't take a hot shower as this will increase the rate at which cooled blood returns to the core and makes the drop faster and deeper. Cold water swimmers have been known to faint in hot showers. Wait until you've warmed up again before showering.
• Get out of the water before you get too cold as you will continue to get colder after swimming – give your body a margin of safety.

• Don't attempt to drive or ride a bike until your core temperature has recovered. Driving and shivering is not a good combination. If your core temperature drops too much and you become hypothermic it can also affect your cognitive abilities. Again, not good for driving.
• Drink something hot and eat something. Shivering is a highly energy consumptive bodily function. You need to fuel it.
• Keep an eye on your fellow swimmers. Someone who appears completely fine getting out of the water may be in trouble 10 minutes later and may need your help.