The breakfast DJ was led blindfolded to a makeshift studio at the top of London's BT Tower, from where his show was being broadcast.
However, HC's main stunt - X-Factor contestant Chico (whose ditty It's Chico Time is currently topping the charts) appearing out of a Pudsey Bear costume - nearly ended in disaster when a porter moved the costume to a storeroom, we hear.
Panic struck as HC's opportunity to hit seven million listeners threatened to disappear, but with seconds to go the suit was found.
'The experience has shortened my life,' reveals HC associate director Justin McKeown.
Diary is glad to hear HC can work in 'Chico time'.