How it works: Whether you’re a backpacker or a whitewater boater, historically, the most common way to treat your water is boiling. Boiling your water for a minute kills anything living. In a high-mountain environment, it may be all you need.
Pros: Cheap—you don’t need any special equipment
Cons: Doesn’t remove chemicals or organic matter floating in your drink. It also takes time and fuel.
What you need: A stove, like Jetboil’s Flash, a campfire, or any other source of high temperature heat.