Years ago, I struggled up to 13800ft in a Chipmunk over Berkshire.....with an horrific hangover from the session in the White Waltham Officers Mess the previous evening!
Young and very stupid - but that was the UAS culture of the time and didn't seem to do many people any lasting harm!
Trying to get down again without knackering the engine was quite tricky, I settled for a series of 2G descending turns and felt even worse.