hot up (v.)

• accelerate
• aggravate
• amplify
• annoy
• augment
• chafe
• complicate
• concentrate
• condense
• consolidate
• cook
• deepen
• deteriorate
• double
• embitter
• enhance
• enlarge
• exacerbate
• exaggerate
• exasperate
• fire
• foment
• heat
• heighten
• increase
• intensify
• irritate
• magnify
• mull
• overheat
• preheat
• provoke
• ramify
• recook
• redouble
• reheat
• reinforce
• sharpen
• sour
• steam
• strengthen
• triple
• warm
• whet
• worsen