15. LifeStraw
Water bottles are imperative for easy storage, but what do you do if you are unsure if the water is clean enough to drink? Water filtration tablets are one option, but you can also pack a LifeStraw in your carry-on to make sure that you will be able to safely stay hydrated during an emergency.
The New York Times praised the LifeStraw for having the ability to filter 99.99 percent of waterborne bacteria and protozoan parasites from 1,000 liters of water. To put this into perspective, one person can use a single LifeStraw to purify all of their water needs for an entire year. In other words, stocking up on LifeStraws is more cost and space efficient than purification tablets, and you should always have one in your luggage.