The phrase "cools out" refers to calming down or relaxing. Antonyms for this phrase include hyperactive, agitated, stressed, worked up, and panicked. To cool out means to take it easy or to slow down, so antonyms would have the opposite meaning. Rather than feeling chill or tranquil, someone who is hyperactive would be frenzied or restless. If one is agitated, they may be restless or nervous. Feeling stressed or worked up would be the contrary of being relaxed, while panicking would be the opposite of calming down. Using antonyms for cools out can help to communicate a feeling of urgency, anxiety, or restlessness.