Well, so much for my precautions against catching colds when you fly. On my latest trip, despite sanitising my hands at every opportunity and spraying tea tree oil up my nose on the outward leg, I had a mild cold on arrival in China and another on returning to New Zealand. Back to the drawing board.
Fortunately, an article I wrote on this very topic just before I left has produced some helpful suggestions.
A couple of readers are fans of Vicks products. Margo Greenville said she, too, "always spent the first week of a holiday with a miserable cold".
But, "I think I have found the answer and my friends, who I have told about it, all report success and they are telling their friends.
"Take a Vicks inhaler in your pocket and put it up your nostrils and sniff it regularly (like about every 20 minutes) on your plane voyage. The worst that happens to me is that I get a violent case of the sneezes, but I arrive well and stay well. I think the camphor in the product disinfects the airways."
And Sandi Jennins wrote, "I always spray Vicks First Defence up my nose after any contact with people with colds and always after a flight. I have been cold-free for four years now since I have been using this. I have had many sore throats but have always done the First Defence thing and it has worked so far."
Jim Davis, from Pharmabroker Sales, wrote to draw my attention to "a unique product called Blis Travelguard developed by Professor John Tagg, the head of Microbiology at Otago University.
It's a natural probiotic vanilla flavoured lozenge that attacks undesirable bacteria and keeps your throat healthy. Blis Travel lozenges gives protection from the re-circulated air conditioning on planes so you don't pick up any unwanted respiratory infections [and] you arrive at your destination healthy."
Davis reckons his company had a comparative test carried out by independent scientists and "Blis outperformed all products". It "showed the most killing power of the harmful Streptococci bacteria and had a long lasting protective effect".
I passed this information on to a colleague who was starting to develop a cold, he promptly bought some Blis - apparently his pharmacist also recommended the lozenges - and he thinks "it definitely helped".
Finally, John Meads wrote to advise that, "I never board a plane without a mask and usually wear it during the flight ... not that this action always keeps me clear of the bot. Bunnings Warehouse currently has packs of four masks on sale for $2.25. Compared with $4.50 for one mask at Auckland Airport this has to be very good value."
So there you go.
Next trip I think I'll try all three approaches. Snuffling while looking at the terracotta warriors or sneezing while spinning prayer wheels at Labrang Monastery isn't my idea of fun.