Title: Hot Weather Affects the London Tube Word Count: 320 Summary: The soaring temperatures on the London Tube over the summer months have been a problem for some years now. Keywords: water, cooler Article Body: The soaring temperatures on the London Tube over the summer months have been a problem for some years now. A London Underground team has attempted to come up with some engineering solutions to the problem by creating a groundwater cooling system. The trial, which starts this summer, aims to make it cooler for passengers on platforms and will be tested at Victoria station which is so deep that it is effectively under water and pumps out 35 litres (eight gallons) a second, to stop it coming through the walls. The idea of the new system is to push the water through a network of pipes into heat exchange units on the platforms, which will suck in warm air and pump out cooler air. The heat could be used to power homes and offices above and this way the temperature will be brought down. But this is only a trial to be tested this year and it is far from being put into work as well as new trains with air cooling systems that are promised for Circle, District, Hammersmith and City and Metropolitan lines. Meanwhile the temperatures in the deepest tunnels, reach 30C (86F) in summer. These changes might affect the London Tube in a drastic way. Some of the Tube lines might be closed especially on the hot summer days. London Underground assures that there are no plans to close any Tube Lines during the summer but in the future years it might get to the point "where the underground will become literally intolerable and you could face the prospect of loss of life" as Mr Livingstone from LU advised. About 1,000 London Tube passengers were trapped for nearly two hours when three trains were held up in a tunnel. The Central Line closed after signal failures stopped the trains between Marble Arch and Lancaster Gate. The trains have been evacuated and three people were treated for the effects of heat.