Boiling can be seen without the help of a thermometer, and by this time, the water is disinfected. Though the boiling point decreases with increasing altitude, it is not enough to affect the disinfecting process. "Boiling" is the method of cooking food in boiling water or other water-based liquids such as stock or milk. Simmering is gentle boiling, while in poaching the cooking liquid moves but scarcely bubbles. The boiling point of water is typically considered to be 100 °C or 212 °F. Pressure and a change in the composition of the liquid may alter the boiling point of the liquid.
Water cooling open systems use inexpensive tap water, but this requires higher blowdown rates than deionized or distilled water. Purified water systems still require blowdown to remove accumulation of byproducts of chemical treatment to prevent corrosion and biofouling. Water cooling also has a boiling point temperature of around 100 degrees C at atmospheric pressure. Engines operating at higher temperatures may require a pressurized recycle loop to prevent overheating. Modern automotive cooling systems often operate at to raise the boiling-point of the recycling water coolant and reduce evaporative losses. The use of water cooling carries the risk of damage from freezing. Automotive and