A heatwave in London is projected to push temperatures up to 33°C (91°F) this Saturday.

The scorching weather this week, reaching its height on the summer solstice, has led many to flock to the capital’s outdoor pools and swimming ponds for relief.

However, officials have issued warnings about the risks of heat-related health issues and swimming safety in natural bodies of water, with the London Ambulance Service (LAS) anticipating a spike in emergency calls.

Additionally, a study by researchers from the London School of Hygiene and Tropical Medicine and Imperial College London (ICL) suggests there could be 129 additional deaths associated with the extreme heat this week.

Nationally, excess mortality from Thursday to Sunday is projected to be around 570 individuals across England and Wales.

By midday, Heathrow Airport had already recorded a temperature of 31°C (88°F).

Researchers underscored the pressing public health risks posed by extreme temperatures in the UK.

Dr. Garyfallos Konstantinoudis, a lecturer at the Grantham Institute at ICL, stated: “Heatwaves are often silent dangers—those who perish during these events typically have underlying health issues and heat is seldom cited as a direct cause of death.

“This immediate analysis highlights the concealed impact of heatwaves, and we aim to raise awareness.”

He emphasized that heatwaves represent an “overlooked danger” in the UK.

Forecasts indicated that temperatures could reach 32°C (90°F) in southeastern England on Saturday, having already done so in London on Thursday.

To alert vulnerable groups to the associated health risks, including potential increases in mortality, the UK Health Security Agency issued an amber heat-health warning throughout England.

On June 13, when temperatures reached 28°C (82°F), LAS experienced a surge in emergency calls, receiving 7,000 compared to the usual 5,500 on a busy day.

To cope with the heightened demand, the service has implemented strategies such as deploying community response vehicles, increasing the number of clinicians available for phone assessments, and expediting patient transfers at hospitals.

Stuart Crichton, LAS’s director of 999 operations, remarked, “We have been exceptionally busy this week and we anticipate an even greater influx of calls this weekend as temperatures rise further.

“We urge London residents to contact 999 only for life-threatening emergencies.”

He noted that the elderly, young children, and individuals with pre-existing health conditions are especially susceptible to heat-related problems.

“Check in on neighbors, family, or friends who may need assistance and ensure they can stay cool during this heat,” Mr. Crichton advised.

Dr. Lorna Powell, an NHS urgent care physician in East London, reported, “We are witnessing an increase in heat-related illnesses within our urgent care facilities.

“Heat exhaustion can quickly escalate to more severe conditions as dehydration occurs and the cardiovascular system becomes strained.”

Andrew Lewington from the London Fire Brigade informed the BBC that there have been 15 fatalities in the capital’s waterways this year alone.

He noted a 15% rise in water rescue operations, averaging 12 calls per week.

“People must recognize what lies beneath the surface of the water and consider their actions carefully before jumping in,” Mr. Lewington cautioned.