intransitive verb
1. : to grow hot, lively, or exciting
the gossip began to hot up — Life
2. : to speed up
the air raids began to hot up about the beginning of February — George Orwell
transitive verb
1. : arouse , annoy
getting him all hotted up — Lord Beaverbrook
2. : to make livelier or speedier
a protest against … the genteel hotting up of Shakespearean productions robbed of all poetry — Stephen Spender