Thermonuclear reactions are the source of the sun's energy.

This house is built using insulation materials.

Please preheat the oven.

Please preheat the oven.

This bacteria can be killed by heat.

This food has been heat-treated to kill bacteria.

He understands the basic concepts of thermodynamics.

When the volcano erupted, a glowing cloud covered the sky.

He said he was feeling feverish and left early.

He prayed fervently for his sick friend.