We had endless spring rain, followed by endless summer days in the 90s. The torrent salmon sun has poured energy upon us while we've tried vainly to sweat that energy away. Our tended plants have done better than people. Understanding heat has been a huge hurdle for science down through the centuries. The word heat originally referred only to what we felt.
Energy flows from the sun by the processes of thermal, visible, and ultraviolet radiation.
We call that movement of energy heat, or heating. As the sun's energy absorbs into our clothing, our skin, and the air around us, our temperature rises. We feel hot. In 1800, our language had no means for identifying the pieces of that process. For one thing, no one yet understood that lifting a brick, and heating a brick in the fire, were both means for conveying energy into the brick.