Dehydration is a surprisingly common problem when you're traveling, so be sure to bring Adventure Medical Oral Rehydrating salt. Diarrhoea, vomiting and sweat loss can all cause dehydration. Or maybe you simply had so much fun, you totally forgot to drink enough the past few days. This World Health Organization formula rehydration mix containing sodium, potassium and glucose will sort you right out. Just add a packet to one liter of water and sip away.