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(CNN) -- Eurostar has specified that its new fleet of trains must be able to withstand high temperatures of up to 55 degrees Celsius, as part of its preparation to adapt to the radical changes expected in Europe's climate in the coming decades.

The company, which operates high-speed trains connecting several northern European cities, including London, Paris and Brussels, had initially ordered around 50 new trains capable of operating in temperatures up to 45 degrees Celsius.

However, the increasing heat waves in Europe, which is the fastest-warming continent in the world, prompted the company to reconsider these specifications.

A spokesperson for Eurostar told CNN in a statement on Friday that the company has asked manufacturers to equip the new trains, with a total value of €2 billion ($2.3 billion), with air conditioning systems capable of operating efficiently in temperatures up to 55 degrees Celsius.

The company spokesperson said: 'These trains will enter service in 2031 and continue operating until the 2060s, so it is essential that we are prepared for the future.'

On Thursday, Eurostar sent an email to its customers offering them the possibility to rebook their planned Saturday trips to another date without any additional fees, due to the very high temperatures.

The email, which a customer shared with CNN, read: 'Several destinations are currently experiencing very high temperatures, and we understand that these conditions may make your journey less comfortable than usual.'

The company added that if passengers decide to keep their original booking, it recommends they bring enough water to stay hydrated.

In an interview with the Financial Times, Eurostar CEO Gwendoline Cazenave said the company is preparing to handle temperatures that were previously associated with countries like Saudi Arabia.

She added: 'This year the heat wave came early, and it was longer and hotter than ever before.'

Large parts of Europe are experiencing a new heat wave, just days after record temperatures were recorded in June in France, Switzerland, Spain and the United Kingdom.

These extreme conditions have put the continent's infrastructure under severe strain, with some trains delayed or canceled due to the risk of metal railway tracks warping from the intense heat.

And air conditioning, long seen in northern European homes as an expensive and unnecessary luxury, is now considered an urgent necessity amid increasing heat waves.