Any other form of energy can be turned into heat, either partially, or
completely; and what
lay folks refer to as «heat» is simply the result of turning some other form of energy; which can include EM radiation; once again, all the way from down to but not including DC, up to the end of the gama ray spectrum (orbeyond), into the
waste mechanical energy of some physical matter; and for most people that is a result of absorption of EM radiation by mostly water in the human body; that's what WE feel as «heat».