Britain recorded its hottest day of the year so far, as the country basked in the heatwave brought by an “enormous” bubble of warm air from the Sahara.

The mercury rose to 34C in Heathrow and other areas of west London on Saturday afternoon – soaring past the 33C highs experienced in the Caribbean island of Jamaica today.

However, the Met Office said temperatures had fallen short of the 35.6C record for June set in 1976.

Emergency services issued warnings to the public to take care in the sunshine, while councils have been urged to bring in measures to protect rough sleepers in the heatwave.

Travellers have been warned soaring temperatures could disrupt the rail and road network this weekend, with Network Rail warning that rails can flex, bend or even buckle in the heat.

Europe seeks relief in scorching Saharan heatwave: In pictures Show all 30 1 /30 Europe seeks relief in scorching Saharan heatwave: In pictures Europe seeks relief in scorching Saharan heatwave: In pictures A zookeeper sprays water on Asian elephants at the Berlin Zoo on 25 June EPA Europe seeks relief in scorching Saharan heatwave: In pictures People cool off in a swimming pool in Hannover, Germany on 25 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures A woman sits on a lawn chair in Lake Wanasee in Berlin on 25 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures An orangutan takes shelter from the sun under a blanket at the Schoenbrunn Zoo in Vienaa on 25 June AP Europe seeks relief in scorching Saharan heatwave: In pictures Visitors shelter from the heat under the Umbrella Sky Project, an art installation in Aix-en-Provence, France on 28 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures A model boat drives past a couple as they bathe in a lake in Ertingen, Germany on 26 June AP Europe seeks relief in scorching Saharan heatwave: In pictures A personal care worker visits the home of an elderly person to help him avoid heatstroke and dehydration during the heatwave in Clermont-Ferrand, France. The heat watch system has been implemented in France, meaning that vulnerable people will have increased access to aid for heat-related ailments AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures A zookeeper applies sun cream to a tapir at the Serengeti Park in Hanover, Germany on 26 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures One motorist in Brandenburg, Germany was stopped by police on account of his tactic for keeping cool on 25 June Brandenburg Police Europe seeks relief in scorching Saharan heatwave: In pictures A German Police helicopter pours water over a forest fire near Lieberoser Heide in Germany on 25 June Reuters Europe seeks relief in scorching Saharan heatwave: In pictures Children jump into the water of Lake Geneva to cool off in Lutry, Switzerland on 25 June AP Europe seeks relief in scorching Saharan heatwave: In pictures Parisians cool off in the fountains at the Trocadero Esplanade on 24 June AP Europe seeks relief in scorching Saharan heatwave: In pictures A polar bear cools off in the Gelsenkirchen zoo in western Germany on 25 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures A woman plays in the in the fountains at the Trocadero Esplanade on 24 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures Children play in Lake Walensee in Switzerland on the evening of 25 June EPA Europe seeks relief in scorching Saharan heatwave: In pictures A refreshments table of water and syrups is laid out at an old folks home in Le Bouscat, France. Due to the heat, extra care provisions are available for the vulnerable in France Reuters Europe seeks relief in scorching Saharan heatwave: In pictures A meerkat reaches for frozen food at the Berlin Zoo on 25 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures People ride down the Old Danube in Vienna on 25 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures A boy plunges into a swimming pool in Essen, Germany on 25 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures A pigeon drinks from a fountain in Mulhouse, France on 25 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures Parisians rest in the shade down by the Seine on 26 June AP Europe seeks relief in scorching Saharan heatwave: In pictures A boy jumps into the canal near Reims in northeastern France on 25 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures People bathe at Amager in Copenhagen, Denmark on 25 June EPA Europe seeks relief in scorching Saharan heatwave: In pictures A walrus feeds on an ice cake filled with frozen fish as her baby looks on i Hamburg Zoo, Germany on 26 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures Children play in a fountain in Nice, France on 26 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures A couple steers an electric boat down the Old Danube in Vienna on 25 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures A polar bear cools off at the Hamburg Zoo in Germany AP Europe seeks relief in scorching Saharan heatwave: In pictures A woman cools of in a water fountain on 26 June AFP/Getty Europe seeks relief in scorching Saharan heatwave: In pictures People lounge on the shore of the Baths of Paquis in Genevs on 25 June EPA Europe seeks relief in scorching Saharan heatwave: In pictures People enjoy the weather in Lake Walensee in Switzerland on 25 June EPA

It comes as police forces across Britain warn the public to stay away from waterways after four people died attempting to cool off from the conditions.

The body of a 12-year-old girl named by the Manchester Evening News as Shukri Yahya Abdi was pulled from the River Irwell in Bury.

Two men, aged 25 and 26, were recovered from the sea near Babbacombe Beach in Torquay. Another man died after being pulled from the water at Cornwall’s Prussia Cove.

Detective Inspector Andrew Naismith, of Greater Manchester Police, said: “With the warmer weather, it’s tempting to go into the water to cool off, but I’d like to remind everyone of the dangers of playing near or swimming in rivers, lakes and reservoirs and would strongly urge against this.”

Met Office meteorologist Greg Dewhurst said the most ferocious heat was seen on Saturday afternoon, “particularly the further south and east you go”.

Festival goers take shelter from the sun on the fourth day of Glastonbury Festival (Joel C Ryan/Invision/AP)

According to guidance produced by the charity Homeless Link, people sleeping rough will be at an increased risk of dehydration, sunburn and sunstroke, as councils were urged to provide free water and sunscreen.

Heather Wheeler, the minister for housing and homelessness, has written to local authorities encouraging them to trigger their Severe Weather Emergency Protocol (Swep) and offer extra support.

Travellers have been warned that soaring temperatures across the UK could bring disruption to the country’s rail and road network this weekend. Network Rail has advised passengers to plan ahead as hot weather could push track temperatures above 50C and slow operations.

Steel rails absorb heat easily and tend to hover about 20C above the surrounding air temperature, according to Network Rail. In very hot conditions rails can flex, bend or even buckle, so trains have to run at slower speeds.

The AA said that roads “soften around 27C”, as gritters were put on standby to spread fine gravel to absorb melted bitumen sticking to car wheels.

However, the Met Office put a yellow warning for lightning in place for parts of Northern Ireland and the west coast of Scotland, as well as a yellow warning for thunderstorms in northeast England and southeast Scotland.

A woman cools off in a water fountain in Marseille as heatwave hits France (Reuters)

The searing heatwave taking hold across Europe saw temperatures soar over 44C in some parts of the continent. Authorities in France have set up “cool rooms” in municipal buildings, opening pools for late-night swimming and installing extra drinking fountains.

Emergency services in Germany urged the public to look out for young children and the elderly, while authorities in the eastern state of Brandenburg have warned of the high risk of forest fires.