Most TMV devices are highly thermosensitive and use thermostats to regulate their temperature. They keep checking temperature as long as the water is turned on, pivoting between the hot and cold valves depending on which is needed to rebalance the temperature. If taps start to supply too much or too little hot or cold water to maintain the balance, the TMV will shut off immediately to keep users safe. Typically, water is kept between 60 °C (140 °F) and 50 °C (122 °F)m which is enough to kill bacteria in the water.