Britons were urged to stay out of the water to avoid fatal cold-water shock as summer finally arrived, bringing soaring temperatures.
The UK Health Security Agency (UKHSA) and the Met Office jointly issued a yellow heat-health alert for England between Monday and Thursday, warning of “significant impacts” of the expected hot weather this week.
The RNLI, the National Coastwatch Institution and emergency services across the UK warned that jumping into water to cool off on a hot day can trigger an involuntary gasp of breath that can lead to drowning.
Accidentally inhaling just half a pint of water can be fatal, experts warned, adding that the phenomenon can affect even the strongest and most confident swimmers.
Cold-water shock occurs in water below 59F (15C). The average sea temperature around the UK and Ireland is just 35.6F (2C), while inland waters, such as lakes, rivers, lochs and reservoirs, can be colder, even in the summer.
‘Open water has hidden dangers’
A spokesman for Derbyshire Fire and Rescue Service said: “When the weather is hot, don’t be tempted to swim in open water.
“It can look inviting but has strong currents, has hidden dangers, is cold and causes cold-water shock.
“Anything below 15C is defined as cold water and can seriously affect your breathing and movement.”
In the last five years, 119 children have accidentally drowned in the UK. Emergency services said that if people wanted to swim in the hot weather they should find organised open-water swim sessions that are supervised by lifeguards.
Cold-water shock also causes your heart rate and blood pressure to increase quickly, which can lead to cardiac arrest.
‘The sea is still chilly’
A spokesman for the East Midlands Ambulance Service NHS Trust said: “Thinking of swimming in open water? Don’t risk it. Jumping into cold water can trigger cold-water shock, causing gasping, disorientation, heart problems and even death.”
The National Coastwatch Institution added: “You can’t beat a day at the beach, but the sea is still chilly with the risk of cold-water shock.”
For people who do get into difficulties in the water, the emergency services recommend relaxing and floating until help arrives.
The yellow heat-health alert has been issued for all of England except the North East, as temperatures look likely to soar to 86F (30C) in parts of the country.
Temperatures are expected to reach the highest in the South East, with the strongest warnings issued for that region, the East Midlands, the East of England and East Anglia.
The UKHSA has warned of an “increase in risk of mortality amongst vulnerable individuals and increased potential for indoor environments to become very warm” for the North West and North East of England, the West of England, the South West and London.
‘The sun will be very intense’
Liam Eslick, a meteorologist at the Met Office, said: “My advice to people would be by all means go out and enjoy. They have been waiting for summer.
“But UV levels are going to be high and the sun will be very intense. Wear protection like sun cream, stay hydrated and try to get some shade in the midday sun. People sensitive to the sun should take particular precautions.”
The hot weather, which could hit official heatwave levels in some areas, is expected to break by Thursday, with thundery, heavy showers and cooler temperatures expected towards the end of the week.
The London Ambulance Service warned that heat can make pre-existing conditions worse and advised people to stay hydrated, use sunscreen, stay in the shade and carry medication.
Signup bonus from
