Clear-looking water can still need treatment
A clear stream or snowmelt can still carry pathogens. Boiling provides a visible treatment endpoint without needing a thermometer.
Bring questionable drinking water to a full boil before drinking it.
The cited CDC Yellow Book recommends boiling for 1 full minute to add a safety margin.
Why consider it?
The number is the treatment duration in this cited traveler guidance, not a measured percentage benefit. The source describes inactivating waterborne pathogens at boiling temperatures. Its elevation discussion concerns common travel elevations; it is not a universal rule for every altitude or a claim to remove non-microbial contaminants.
Read the sources
Source grade B is reproduced from the original work. It does not establish suitability for everyone.
Original item: chapter 13, item 35 ↗Adaptation: Rewritten in English from the locked Chinese original; retained evidence grade and study limits. Effect sizes quoted from the cited source: no quantified effect of the proposed action is claimed; numbers, where present, are descriptive findings, study procedures or guidance parameters.
Make space for a practical habit.
Add this idea to your local checklist.