 In places having a proper water purification system, it is recommended only as an emergency treatment method or for obtaining potable water in the wilderness or in rural areas, as it cannot remove chemical toxins or impurities.The elimination of micro-organisms by boiling follows first-order kinetics—at high temperatures, it is achieved in less time and at lower temperatures, in more time.The heat sensitivity of micro-organisms varies, at , Giardia species (causes Giardiasis) can take ten minutes for complete inactivation, most intestine affecting microbes and "E. coli" (gastroenteritis) take less than a minute; at boiling point, "Vibrio cholerae" (cholera) takes ten seconds and hepatitis A virus (causes the symptom of jaundice), one minute.