There are several antonyms for the phrase "slow burns." Some of these include quick explosion, rapid ignition, fast flare-up, and sudden eruption. These phrases describe sudden and almost immediate reactions, rather than a slow and gradual increase in intensity. They are often associated with extreme emotions or situations, such as anger, excitement, or danger. Antonyms for "slow burns" tend to evoke a sense of urgency or intensity, and are often used in reference to dramatic events or experiences. Overall, the variety of antonyms for "slow burns" reflects the many different ways in which we experience and express strong feelings.