Heath turned professional in 1994 after graduating from the University of Glasgow. He spent eleven years on the professional tour, including six consecutive years ranked in the world's top 10. His career-high ranking was World No. 4, which he reached in 1999. He won the Scottish national squash title six times. In 1996, Heath won the Singapore Open and repeated again in 1997, both times without losing a game. However, it was not until 1998 that Heath made his debut in the top 10 at No. 7 by reaching the final of the Al Ahram International, beating World No. 1 Peter Nicol in the semi-finals. At the time, the Al Ahram event was the largest purse to date at $175,000. In 1999, Heath reached the semi-finals of the World Open, losing to eventual champion Peter Nicol 3 to 1. In 2000, he finished runner-up at the Tournament of Champions in New York City (beating Peter Nicol in the semi-finals, before losing to Jonathon Power in the final). His last competitive year was 2002 in which he reached the semi-finals of the Pakistan Open and quarter finals at the British Open and World Open.
Since retiring as a player in 2004, Heath has worked as a coach and sports journalist, writing a column for Squash Magazine and commentating on many PSA tour events as color and lead commentator. Heath is currently the Head Squash Coach for the University of Rochester men's varsity squash team, the "Yellowjackets". Heath led the team from a pre-season intercollegiate (CSA) ranking of No. 28 in 2005 to No. 3 in 2009. The Yellowjackets reached the semi-finals of the CSA National Championships in 2009, 2010 and 2011.
Heath also coached the US Junior Men's Team from 2007 to 2011, leading the team in Switzerland in 2008, India in 2009 and Ecuador in 2010. Heath was honored for his work with the National Team and his success with the University of Rochester by being named US Olympic Committee National Coach of the Year 2010.
Heath is married to Canadian Fenella Rawana and has a three years old son, Kamren Heath; they live in Toronto, Canada.