Actually what happens is tha protiens break down at about 160 to 180 degrees. Fortunatelly this is juat about the boiling point of water on the top of Mt. Everest. So it is safe to bring the water to a full boil at any elevation and the water is safe. The ony eception to this is the thermophiles found in Yellowstone and some deep sea trenches but I do not think any of these are pathogens.
cheers