There's nothing worse than that feeling – that first scratching in the throat, that first rumble in the stomach, that first dull ache in the brain – when you know you're about to get sick.
For travellers it seems to happen pretty regularly. It's impossible not to expose yourself to all sorts of weird germs when you travel. You're eating strange things, you're sleeping in strange places, you're sharing air space and occasionally bodily fluids with people you've never met.
The chances are high that you're going to get sick. And people do. A recent survey by vaccine company Sanofi Pasteur found that about half of all travellers reported getting some sort of illness on their last trip away. That could be anything from Delhi Belly to a full-blown virus or disease.
As someone who had a very recent trip overseas marred by illness, I can tell you, it's not fun. But if you really insist on getting sick while travelling, here's how to go about it.
Don't do any research
That same Sanofi survey found that more than half of travellers don't visit their GP before they go overseas. And that's the bare minimum of research you should be doing. Is there malaria where you're going? Or dengue fever? Or the Zika virus? There could be a break-out of cholera. Or just a lot of people getting food poisoning. It pays to know before you arrive.
Disobey the golden rules
Here are the golden rules of eating when travelling: if you can't boil it, cook it, or peel it, then don't eat it. Unfortunately if you stick to these golden rules then you'll have a pretty boring holiday, so the idea is to just not take too many risks.
Visit friends or relatives
There's a funny thing that happens to people when they go to visit friends or relatives overseas: they assume they can't get sick. They either figure they have some sort of natural immunity, or they decide that staying with people they know will protect them. Neither of those things is true.
Don't get vaccinated
One in two travellers don't get vaccinated before they go overseas. So they apparently don't worry about hepatitis, or yellow fever, or meningitis, or cholera, or any of those nasties that it would be pretty simple to protect against just on the off-chance you're exposed to it.
Just getting on a plane exposes you to the germs of about 400 people or more. Flying around in that glorified petri dish, you're bound to be at risk, and there's really not a lot you can do about it.
See also: How safe is cabin air?
Drink the ice
This one isn't easy. After all, if you were to be regimented about avoiding ice in your drinks you'd miss out on iced coffees in Vietnam, and those cool, slushy drinks in Thailand, and frozen margaritas in Mexico. You can ask if they use filtered water, but the answer will probably be yes, regardless of the truth.
Brush your teeth with tap water
Don't do it. It may seem easy, and it may seem natural, but if you're not drinking the tap water, then you don't want to be brushing your teeth with it either. It's the same water! And just because you're staying in a nice hotel, doesn't mean the water is any better than the dodgy hostel down the road.
Eat bad street food
There are some who would advocate not eating any street food at all, but where's the fun in that? Some of the world's best food is served on the street. The trick is to look for popular vendors who cook the food in front of you. That will give you the best chance of survival.
Swim in dodgy water
I've taken a dip in a few extremely questionable south-east Asian rivers, and there are plenty of travellers who've done similar things in India, or Sri Lanka, or parts of Africa or South America. If you have a feeling that the water is polluted, then best advice is to not go in there.
Well-cooked eggs are fine. However, when they're runny, that's when they can contain salmonella. It's a low risk, but still, it's there. There's also risk in eating ice-cream when you travel, and any unpasteurised dairy products (although I'd like to see you stick to that in France or Italy).
Don't bother with mozzie repellant
Some of the most worrying nasties out there at the moment – malaria, dengue fever, Zika, chikungunya – are spread by mosquitoes. It might seem like a pain, putting repellant on every day, but the alternatives are much worse.
Don't wash your hands
This is a pretty simple one, and yet there are still plenty of travellers out there who don't wash their hands regularly, mostly because there isn't always soap nearby when you're travelling. Carry a little bottle of hand sanitiser with you.
Don't pack any medical supplies
When I first started travelling I'd carry a full first-aid kit everywhere I went. These days I've done well if I remember to throw in some Panadol. There should be a happy medium there somewhere.
Don't drink enough water
When you think about it, beer is made from water, and so really, drinking a lot of beer should be enough to keep you hydrated when you travel. Unfortunately that doesn't always seem to work out well, which is why I try to carry Hydralyte tablets as well.
They seem like the healthiest thing you could be eating – unfortunately though, salads are one of the riskiest dishes for travellers. Most salads are made with fresh vegetables that are washed in tap water. The same tap water you've studiously been trying to avoid. Stick to something deep-fried.
What are your tips for staying healthy while travelling?