as well its not just in the cockit, i actually find myself sneezing and itchy-eyeing as well after sleeping in the crew bunk.
There was a time when fresh sealed blankets were available every time out of HKG. Not anymore - the ones we pick up have probably been in use for days on end.
Is the level of sickness tied up with cleanliness levels on the jet? Those 'pre-pneumatic' toilets are a bit of a health risk too.