The most critical point in preparing a great steak isn't when you start cooking - it's when you stop. The proper degree of doneness is absolutely essential to enjoying steak.
There may be a number of reasons why it is difficult to determine the temperature of steak cooking on a grill: A steak may be too thin to use a thermometer, or uncertain light may make reading it difficult or impossible.
There is, however, an easy test that will tell you the degree of doneness of a 1-inch-thick steak. It demands some practice with the following exercises, but the touch test is a valuable addition to the grill magician's bag of tricks.
For rare: Let one hand hang limp. With the index finger of the other hand push gently into the soft triangle of flesh between the thumb and index finger of the hanging hand. It will offer very little resistance, give way very easily and feel soft and spongy. That is the feel of rare steak.
For medium-rare: Extend a hand in front of you and spread the fingers. Press the same spot with the index finger of the other hand. The flesh will be firmer but not hard, springy and slightly resistant. That is the feel of medium-rare steak.
For medium: Make a fist and press the same spot. It will feel firm and snap back quickly, offering only a minimum of give, as does meat cooked to medium.
Cooked further, your steak is a lost cause.