Gloria Hunniford, Angela Rippon and Julia Somerville investigate problems viewers have experienced around some holiday essentials, getting to the bottom of which countries are ones where it is, or isn't, safe to drink the tap water, and testing out the most effective ways to beat travel sickness. Also, as travellers reveal how they have ended up out of pocket thanks to pre-paid currency cards, there is advice on how to avoid ending up in the same position. And Simon Calder has advice on visiting California.