Britons are being warned of a hidden health risk lurking in their gardens as soaring temperatures create ideal conditions for a potentially deadly disease to spread in hot tubs and swimming pools.
Heatwave Sparks Legionella Warning
The alert comes as forecasters predict temperatures could reach 28C this week, bringing the start of another hot spell after weeks of rain and grey skies across much of the country. Experts say warm weather can increase the risk of Legionnaires' disease, a potentially fatal lung infection caused by inhaling tiny droplets of water contaminated with Legionella bacteria.
The bacteria can thrive in stagnant or poorly maintained water systems, including domestic hot tubs, spa pools and swimming pools.
Growing Popularity of Hot Tubs
The warning follows new research showing the growing popularity of such leisure products in British homes. The survey found that one in 10 Britons now own a hot tub or jacuzzi, meaning there are almost three million in operation across the UK. A further 13% of people said they own a swimming pool or cold plunge bath.
Despite their widespread use, the findings suggest many owners are failing to follow basic maintenance routines. More than half of hot tub owners, 54%, admitted they were not fully confident that their cleaning and maintenance procedures were robust enough to keep users safe. Among those questioned, 28% said they had either not considered or preferred not to think about hygiene risks and germs associated with the devices.
The research also found only 24% of owners follow a set cleaning schedule, while a staggering 92% do not regularly test for Legionella.
Expert Warning
Greg Rankin, chief executive of water safety specialist Hydrohawk, said the threat posed by the bacteria was often overlooked: "As temperatures rise, it's easy to get caught up in the excitement of barbecues and evenings outdoors. However, behind the scenes, Legionella remains a silent yet serious threat, especially in warm, stagnant water systems such as unused hot tubs or spa pools."
Mr Rankin warned that rising temperatures and increasingly extreme weather patterns were creating conditions in which Legionella bacteria can flourish: "It has never been more important to raise awareness and take preventative steps."
Legionnaires' disease is estimated to affect between 4,000 and 6,000 people in the UK each year. Between seven and 12% of infections prove fatal, according to figures cited by the company.
Why Hot Tubs Are a Risk
Experts say hot tubs present a particular risk because they typically operate at temperatures between 25C and 45C — the same range in which Legionella bacteria can multiply. The use of jets and water sprays can also increase exposure by creating fine airborne droplets that may be inhaled.
Periods of intermittent use are considered especially hazardous. When a hot tub is left unused, water can stagnate inside pipework, filters and fittings. Disinfectant levels may fall while biofilm accumulates on internal surfaces, creating an environment where bacteria can thrive.
As a result, owners are being urged to thoroughly drain, clean and disinfect hot tubs before using them after a prolonged period of inactivity.
Preventative Measures
Mr Rankin said homeowners should ensure water has been treated with the correct chemicals before switching systems back on: "Chlorine and bromine are the most commonly used disinfectants and can help keep the risk to a minimum."
He also recommended regular Legionella testing to identify potential problems before they pose a danger.
With temperatures set to climb and millions of Britons preparing to make the most of the sunshine, experts say taking simple maintenance precautions could help prevent a relaxing summer pastime from turning into a serious health risk.
