Why is the use of voltages exceeding 36 V prohibited in practical work?

The human body, which is mostly liquid, is a good conductor. Only a significant resistance of the hardened skin of the hands prevents the flow of a high current through the body. Therefore, at low voltages of several volts, a current of a fraction of a milliampere flows through us, which we do not even feel. But already starting with a voltage of U = 36 V, an increased current strength can cause a noticeable biological effect, and a current with a strength of more than I = 100 mA, as a rule, is fatal.