1.   Any two surfaces rubbing together produce frictional heat, such as a brake shoe pressing against a brake-drum.

2.   Heat can be produced by chemical reactions or friction.

3.   The boiler burns oil to produce heat.

4.   And because the Serbs often turn tank engines off to conserve fuel, they often do not produce enough heat to be detected.

5.   Because the lights produce heat, you might need to replace older power-supply lines that might not be rated to withstand heat.

6.   A. Modern efficient light is based on the goal of producing light without producing wasted heat first.

7.   Endless Summer heaters produce radiant heat that heats surfaces, including the skin and clothing of people nearby.

8.   He heated them with a known quantity of energy and measured how much heat was produced.

9.   I was wondering if I could cut that pipe and install a finned pipe in its place to produce more heat.

10.   If they worked, such reactors could produce enough heat, with the same process that makes the sun and other stars shine, to drive electric generators.