The Romashka reactor family uses uranium and direct thermoelectric conversion to electricity, rather than using a heated fluid to drive a turbine.

Heat storage for power production during cloudy and overnight conditions can be accomplished, often by underground tank storage of heated fluids.

The heated fluid not only melts ice but helps dissolve splattered bugs and oily road grime.

At the heat source of a system of natural circulation, the heated fluid becomes lighter than the fluid surrounding it, and thus rises.

Out in deep space, a heated fluid is circulated through the tube, keeping the temperature of the conductor above it's superconductivity point.

The heated fluid is cooled and reused over and over.

In addition to the classical use of power generation, further uses for the heated working fluid can include desalinization, process heat, and district heating and cooling.

Prolonged exposure to air contaminated with heated hydraulic fluids and oils, as can sometimes happen in passenger aircraft.

With cocurrent or parallel exchange the heated and cooled fluids can only approach one another.