asked Her Majesty's Government:

Whether they have discussed, or intend to discuss, with the Mayor of London and Transport for London, contingency plans in the capital should the Underground become impossible to operate in whole or in part during the predicted high summer temperatures because of excess heat within the system. [HL3530]

Officials at the Department for Transport discuss contingency planning with Transport for London and London Underground on a regular basis. However, the preparation, contents and implementation of these plans are operational matters for London Underground.