The pool is heated using electricity generated by themselves and is kept at a constant temperature of 32 degrees — wonderfully warm, even on a chilly winter's day. (visitcornwall.com)
Also, stars on the main sequence brighten slightly at a constant temperature as they age so they move slightly vertically on the main sequence. (astronomynotes.com)
In this example, because the system is holding both surfaces at a constant temperature we have a constant (and continuous) flow of heat between surfaces. (scienceofdoom.com)