It would have 'melted your heart' [=it would have filled you with compassion, sympathy, etc.] to see her lying in that hospital bed.
Her anger 'melted away' when she saw that he was truly sorry.
He seemed to 'melt into' thin air. [=he seemed to disappear]
(..) You've got to be kidding me. You blew the trick. I most certainly did not! I molded you the perfect spoon! BRENNAN: Gallium melts at degrees. You obviously warmed the water just enough so it wouldn't steam. (..)2015 TvShow: Bones Title: The Promise in the Palace Season: 11 Episode 7