With an increased capacity of ten percent and walk-through air-conditioned carriages, the new trains have improved accessibility and are more energy efficient. They are currently undergoing driverless trials in Germany and were also spotted in Austria (they were made in a factory in Vienna).
Wear light clothing. Even if you think you might need to wear a jacket, when you are on the hot Tube, it's likely you'll want to take it off immediately. Heavy, dark, thick clothing will make you more likely to sweat, and hold on to the sweat your body does produce – keeping you hot and clammy for longer.
In July and August, the average tube temperature can be over 29°C. Note: The Deep Level lines are Bakerloo, Central, Jubilee, Northern, Piccadilly, Victoria, and Waterloo and City. Sub-surface lines are the Circle, Hammersmith & City, District and Metropolitan lines.