The capital's transport network is notorious for being completely unbearablein the heat.Temperatures soared to 36.5C on some buses, according to the , while the Central line reached 33.7C during rush hour yesterday evening.To put this into perspective, it is illegal to transport cattle in these temperatures.So it's easy to see why people were annoyed when TfL, the puppet master orchestrating our heatwave misery, tweeted this little boast yesterday:'Good morning everyone,' Matthew wrote. 'This week I will mostly be thankful for air conditioning.'In response one Twitter user, @DigitalJuiceUK, wrote: 'I kinda don't see this being an appropriate tweet from TfL. People have to sit on the Tube in this heat.'Meanwhile, the TfL account was bombarded with people complaining about the excruciating temperatures.Mark Evers, Director Customer Experience, London Underground, said: 'Our investment in cooling the Tube includes improving ventilation systems at our stations and introducing new air conditioned trains, which will serve 40 per cent of the Underground network by the end of this year.'Around two thirds of double deck buses, including every new bus entering our fleet, is fitted with an upper-deck cooling system.'The vast majority of buses also have white roof panels which help to reflect the heat and many buses have insulated roof and side panels which reflect heat along with tinted side glass.'A spokesman added that in order to combat the heat and prevent people getting seriously ill, TfL are planning to hand out 250,000 free bottles of water at Underground stations today.The Evian giveaway is part of TfL's Travel Better London campaign.