This cannot be overstressed. The voltages found within most HPAs are indeed...
LIFE
THREATENING!
Some Information about High Voltage
As little as 10 to 15mA (0.010 to 0.015A) can stop your heart. Therefore your resistivity plays a key role in your survivability when it comes to Electric Shock. When working around High Voltage, always wear rubber soled shoes and keep one hand in your rear, pants pocket. Do not wear any rings, bracelets, watches or any type of jewelry. Do not wear loose clothing that may get caught on something should you need to retreat quickly. Do not let any part of your body touch the HPA Cabinet while working around High voltage.
Remember that Nature does not like High Potentials and is constantly seeking equilibrium. You can do everything right and under certain circumstances, High Voltage will “reach out and touch you.”
When working on or around High Voltage always have someone else nearby to assist you; to kill the power and call for help in the event of electric shock.
When assisting someone who is working on or around High Voltage, never get within reaching distance of that person. Should that person be shocked, they may reach out and grab or touch you leading to your incapacitation. (That means you might be shocked as well.) If the person you are assisting is seriously shocked, kill the power, and call 9-1-1 or emergency services. Use a non-conductive rod or piece of wood (wooden broom handle) to separate the shocked person from the electrical equipment. (Capacitors can store a charge for quite a while.) Once the person is separated from the equipment, perform CPR if the person is unconscious, not breathing or without a pulse.
Never work on or around High Voltage when you are tired, distracted, or under the influence of any drug or alcohol.
Never attempt to adjust the filament voltage or related trip circuitry in any HPA when the Unit is in Transmit! (People have died in the process of doing this!) Always try to prevent the HPA from being able to go into transmit or disable the High Voltage Power Supply. If possible, disconnect the High Voltage Power Supply from the filament circuitry prior to making adjusments or calibrations.