Yes, it is true and it is not idolatry. There is a section in the Torah in which a “copper snake” was made by Moses as an antidote for a plague that befell the Jewish People in the desert (Num 21:5-9). The plague was a punishment for the Jewish People ungratefully complaining about being in the desert, although they were provided with all their needs and were on the way to Israel. The Torah describes the snake as being placed on the top of a tall pole.
The Torah teaches the method of healing: when anyone who was affected by the plague and would otherwise die, “when he looks upon it (the copper snake) he shall live.”
As you ask, doesn’t this seem to resemble idol worship by looking to the snake on the pole for life? No. Our Talmudic Sages teach, "Could a snake on the pole cause death by not looking at it or give life by looking at it? Of course not! Rather, when Israel looked upward and subjected their heart to their Father in Heaven they would be cured; but if not, they would waste away".
Their healing depended on understanding that our lives are above the natural order. By looking upward they repented and reaffirmed their faith in God and His healing power, and were cured.
By the way this depiction of a snake on a pole as described in the Torah is the emblem and symbol of the Israel Army Medical Corps today.
