What seems like a few minutes to an accelerated individual goes by much more quickly to an individual experiencing time conventionally. In fact, a person in normal time cannot see a hyper-accelerated individual because he or she moves too fast. An individual in normal time hears a sound like a buzzing insect when in the presence of a hyper-accelerated person, which is really the sound of their speech, sped up to a very high rate.
When making the transition from normal time to accelerated, an individual's life span is shortened. In addition, they are susceptible to cellular damage, which can result in the person aging to death in mere minutes as a result of the slightest injury. (TOS: "Wink of an Eye")