Used when someone is being literally or figuratively chased, creating urgency or tension. The detective was right on the suspect's heels, closing the gap.
Pro Tip 2/3
Competition
Often used to describe a close contest where competitors follow each other closely. She's leading the race, with her rival hot on her heels.
Pro Tip 3/3
Intensity
Illustrates the intensity of the pursuit and the narrow distance between two entities. The guard dog was on the intruder's heels as he tried to escape.