My mk1 fabia vrs is the first car I've had with air con, which I absolutely love on those occasional hot days or afte a hard sesh in the gym. However I sometimes find, mostly on longer journeys that even though I've set it to blow cold, it randomly starts blowing hot. Sometimes for a few seconds, sometimes minutes. Anyone know what is likely to be the cause? I've got to drive to bristol next week in my suit for a job interview and would prefer not to turn up drenched in sweat :/

I've got the same problem in my car too (except the random blasts of hot air happen with or without the AC switched on).

I've been led to believe that is a sign of a faulty temperature motor flap, about £70 for a new one too

If you have or know someone with VCDS get them to scan for fault codes. A faulty mixer flap will flag up a fault code. Mine brings up an intermittent fault code for this although i've never noticed any issues with the air temperature. I beleive the mixer flap is a common fault, whether intermittent or continously malfunctioning.