had to do a session of 5 x 10min at 240-260w and couldn't complete the last two due to lack of energy and overheating. excuses - did not have any breakfast, went to a spinning class for a warm-up (took it easy), then did a session on a wattbike in a gym, which is great, however there are no fans in front of wattbikes and i got way too hot when doing intervals.
i will either talk to the gym about installing fans (which i think is unlikely) or i will have to continue training at home..