Implies someone is being closely followed, often in a literal chase or pursuit. As soon as the gates opened, the sprinter was hot on the rival's heels.
Pro Tip 2/3
Urgency and Pressure
Suggests a sense of urgency or creating pressure for the person being followed. With deadlines approaching, her manager was hot on her heels for project updates.
Pro Tip 3/3
Competitive Context
Often used in sports or competitions to describe a close margin between competitors. The young athlete was hot on the champion's heels, threatening to take the lead.