Book 30, Question 115
How do campers make lake water safe to drink?
Hikers often use two steps.
First, a filter takes out dirt and many germs. Then they add something that kills the rest, like boiling the water for at least a minute, using purification tablets, or using a UV pen. Each method works differently, and grown-ups need to follow directions exactly. Boiling water is hot, so it needs care and patience to cool.