In message , John
writes
Last year our mate Ken made lots of noises about requiring TfL to get on
with cooling the tube, etc. It all seems to have gone quiet - anyone
know whether any progress has been made?

Only mention I've seen recently on the posters about carrying water in
hot weather refers to "new technologies" for cooling the tube.
Maybe they are looking into geothermal heat pumps...
--
Kat Me, Ambivalent? Well, yes and no.