Outdoor swimmers have been warned about the risks of hypothermia after a spate of incidents at a public lido.
Organisers at Parliament Hill Lido in Hampstead Heath, north London, say lifeguards dealt with a hypothermic swimmer every day last week, following a sudden drop in outdoor temperatures.
Water temperatures at the unheated outdoor pool, which is open 365 days a year, dropped to as low as 8C (46.4F) last week.
NHS experts say hypothermia, which can be fatal if untreated, occurs when the body’s internal temperature drops below 35C.
Swimmers using the pool have now been warned not to spend too long in the water.
In a post on social media, Parliament Hill Lido wrote: “The water temperature has dropped like a stone and is now sitting around 8.
“This is significantly colder than it was just a week ago, yet a number of swimmers are still trying to stay in the water for as long as they did last week
“This week, the lifeguards have dealt with at least one hypothermic swimmer every day, and they are becoming concerned that people are not taking the temperature seriously.
“Please look out for yourself and other swimmers and please don’t stay in the water too long.”
According to the NHS, hypothermia is a medical emergency that requires hospital treatment.
Symptoms include shivering, slurred speech and tiredness or confusion. One of the main symptoms is pale, cold and dry skin and blue-coloured skin and lips.
The NHS advises anyone who thinks a person has hypothermia and has any of the above symptoms to go to A&E or call 999.
Outdoor swimming experts, meanwhile, say there is no accurate way to preemptively estimate how long a person can safely spend in cold water as it is different for each individual and can depend on a number of factors including size, body fat percentage and physical fitness.
Outdoor Swimmers’ Handbook author Kate Rew told Sky News: “Winter swimming is a fairly brutal physical experience but a lot of swimmers find it fun – if you love rivers, lakes and the sea you can get separation anxiety not saying hello to outdoor water if you don’t swim from September till the following May.
“It takes bravery to get into ice-cold water, and you will be rewarded by a sense of achievement and shot of adrenalin if nothing else.”
Outdoor swimming has become an increasingly popular hobby in recent years, with many claiming it to be beneficial to health and mental well-being.
Symptoms of hypothermia, according to the NHS
- Pale, cold and dry skin – their skin and lips may be blue
- Slurred speech
- Slow breathing
- Tiredness or confusion
A spokesperson for the Hampstead Heath charity which runs the Parliament Hill Lido, and which is managed by the City of London Corporation, said: “We are urging swimmers to follow our cold water swimming guidelines, especially during the recent drop in temperatures.
“There are risks associated with cold water swimming, even for regular winter swimmers.
“We are advising people to swim with care and only spend a short amount of time in the water.
“The Parliament Hill Lido is staffed with fully trained lifeguards to help keep swimmers safe.”