Source : WordNet®

hot up
     v 1: gain heat or get hot; "The room heated up quickly" [syn: {heat},
           {heat up}] [ant: {cool}]
     2: make more intense; "Emotions were screwed up" [syn: {heat up},
         {screw up}]
     3: make more powerful; "he souped up the old cars" [syn: {soup
        up}, {hop up}]