How Does Electricity Cause Harm?

We should always take a safe and curious approach when around electricity and in a medical setting, it is no different. In a medical setting when current passes through a body, it will produce heat. Sometimes this heat is a desired effect and is used by some medical equipment. These medical surgical units may be used to cut, burn unwanted tissue or coagulate blood or other stuff in the body. Low-frequency a.c. signals applied to human tissue can cause a tingling sensation, muscle spasms or even death.

The heartbeat of the human body is from 0.5 Hz to 240 Hz. Therefore, our electrical system is right within this range and can disrupt normal cardiac rhythms. Particularly you should pay close attention to moisture, even large amounts of sweat that could create greater risk.

Below you see a power supply/charger. Have a look at the image, then take an educated guess on if it is a class I or class II appliance. Drag your answer to the center of the image.