Don't drink the water

The water in South America is universally unfit for the western stomach. It comes out of the tap pretty clean, but swimming with micro-organisms that could wreck your night (and probably the following day). The lonely planet is also quick to point out the bottled water is largely unregulated and could cause the same problem. There are also cautions surrounding salads or fruits washed with tap water and drinks containing ice.

I went with a UV purifier (and micropur tablets as a backup) as our lightweight solution to the water problem. Some point out the benefit to the environment by passing on bottled water. But the real advantage here is it gives you immediate access to drinkable water whenever you need it. I remember running out of water at the worst possible times on previous travels. Imagine waking up in the middle of the night (fully parched hungover and in Bangkok of all places) and finding you've got nothing at all safe to drink.

So, on a friend's recommendation, I went with the steripen freedom. It gives you something like 40 48-second UV purifications on a charge and then water is drinkable immediately. I got this little guy on REI's website for $119 or so. Better still, you can use your iPhone charger block (5v/1a output) with steripen (to mini USB). That's less stuff in your pack!