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Heart Breakfast with Jamie Theakston and Lucy Horobin 6:30am - 10am
The first air conditioned tube train arrives on the MET line today. Just one for now but 190 others are on the way.
The trains on the MET, Circle and Hammersmith and City Lines are costing more than £1.5B, have walk-through carriages and better CCTV.
The Mayor says you'll be 'cool as a cucumber'. Work continues to find ways to cool the deeper tube lines.