Before attempting any kind of repair on an electric vehicle you should familiarize yourself with the safety guideline supplied by the vehicle manufacturer.
Hand tools should conform to European safety standard EN 60900.
Figure 18: Rubber insulated spanner conforming to En60900
Protective gear includes rubber gloves, protective eyewear and a rubber blanket.
Figure 19: EV mechanic wearing proper protective gear (DTI)
Jacking, lifting, supporting is prohibited in areas where high voltage cables are routed. Typical such places are the center axis of the car (of the main drive shaft tunnel) or where the fuel tank would normally be. Refer to the vehicle manual.
Electric cars and hybrid cars contain roughly the same type of traction batteries. The voltage of these batteries is typically 360-400 Volt. This is a lethal voltage and it is potentially enough to allow electricity to travel through thin air. This can happen if an electric arc is allowed to form between the battery plus and minus connections. Even the slightest contact between the two poles could start an electric arc.
Figure 21: In the worst case electric arcs can form, allowing electricity to travel through air (picture from Wikipedia)
The amperage of traction batteries is very high, up to several thousands of amperes if short circuited by e.g. and electric arc.