If it is the current that causes the damage why do dangerous places have signs warning you of the high voltage?

Answer 1

True, current causes the damage. But current cannot flow unless there is voltage present to push it. Imagine a live, exposed wire sticking out of a wall. It has voltage, but that's all. No current flows until the circuit is completed by something. That something can be you! At the instant you touch the wire, current flows from the wire, through you, and into the ground. If the current is high enough, it can injure or even kill you. The higher the voltage, the more current will flow once you touch the wire. A sign warning of high current would be inaccurate, because before you touch the wire, the current is zero. And low voltages cause very little current to flow through a human body under normal conditions. So, high voltage does indeed pose a potential threat, and thus warrants a warning. It's like the flammable warning on a can of gasoline. Right now, it just sits there. It is not hot, there is no flame. Yet. But we both would agree it has the potential to burn us to a crisp under the right conditions. Gasoline is not what hurts you. The flame it produces is what does the damage, yet we still put the warning on the gasoline. Voltage is like that. It's the current (flame) that does the damage, but it comes from the voltage (gasoline), so that's what we warn of.