With Britain still basking in a heatwave and temperatures set to rise even further over the coming days, revellers have been warned of the dangers of jumping into Axmouth harbour.

A local fisherman recently took to Facebook to warn of the dangers amid increased incidents of young adults jumping into the River Axe in front of boats navigating their way into the harbour.

There are signs warning against this activity but the fisherman said some swimmers had offered rude responses when approached.

"Please can I ask, that this information can be passed on to anyone who has children that may be going down to the harbour, that they refrain from entering the water from the wall particularly when vessel are entering or leaving the harbour," he added, saying this may result in serious injury.

Emergency services have also previously advised against jumping into the River Axe from Axmouth harbour, as strong currents have seen people swept out to sea in the past.

The RNLI have also warned of the possibility of cold water shock as more people take to the water during the heatwave weather.

Anything below 15°C is defined as cold water and can seriously affect your breathing and movement, so the risk is significant most of the year.

Average UK and Ireland sea temperatures are just 12°C, even during warm weather.

What are the cold water shock symptoms?

Cold water shock causes the blood vessels in the skin to close, which increases the resistance of blood flow. Heart rate is also increased. As a result the heart has to work harder and your blood pressure goes up. Cold water shock can therefore cause heart attacks, even in the relatively young and healthy.

The sudden cooling of the skin by cold water also causes an involuntary gasp for breath. Breathing rates can change uncontrollably, sometimes increasing as much as tenfold. All these responses contribute to a feeling of panic, increasing the chance of inhaling water directly into the lungs.

This can all happen very quickly: it only takes half a pint of sea water to enter the lungs for a fully grown man to start drowning. You could die if you don't get medical care immediately.

How to deal with cold water shock and minimise the risk

If you enter the water unexpectedly:

• Take a minute. The initial effects of cold water pass in less than a minute so don't try to swim straight away.
• Relax and float on your back to catch your breath. Try to get hold of something that will help you float.
• Keep calm then call for help or swim for safety if you're able.

If you're planning on enjoying the water:

• Check conditions - including water temperature - before heading to the coast. Visit metoffice.gov.uk for full surf reports in the UK and Ireland.
• Wear a wetsuit of appropriate thickness for the amount of time you plan to spend in the water and the type of activity you're doing, if entering.
• Wear a flotation device. It greatly increases your chances of making it through the initial shock