A thermal immersion circulator is an electrically powered device that circulates and heats a warm fluid kept at an accurate and stable temperature. It is used in various processes, but starting in the late twentieth century, these devices have also been used for sous-vide food cooking, a method that uses airtight plastic bags in a water bath at regulated temperatures much lower than usually used for cooking. A thermal immersion circulator comprises a circulator pump to move the fluid, a heating element, a temperature gauge, and control circuitry which works to stabilize the temperature. Scott Heimendinger, who previously worked at IBM and Microsoft and was a Director of Applied Research at Modernist Cuisine, created this prototype immersion circulator which ultimately became the commercially successful Sansaire Sous Vide machine launched in 2013.