On the Heels or on the Heals?

Directly behind, immediately following, as in Mom's birthday comes on the heels of Mother's Day, or Hard on the heels of the flood there was a tornado. The hard in the variant acts as an intensifier, giving it the sense of “close on the heels of”.

What does the phrase on his heels mean?

Also, on someone's heels. Immediately behind, in close pursuit. This idiom is used both literally, as in Jean's dog was always at her heels, and figuratively, as in Although his company dominated the technology, he always felt that his competitors were on his heels.

What does right on the heels mean?

following someone very closely; following very closely at someone's heels.