For example, the jaws of life usually are employed by cutting the car at the roof support. In hybrids, a high voltage cable runs through this area. Cutting through it with a tool like the jaws can create a ground fault. Batteries are DC, which produces a more damaging current physically than AC (although AC can cause a heart palpitation that can easily kill you). More likely you will damage the equipment, but it does pose a danger to the EMTs.
Hybrid vehicles have very high voltage, up to 500v. Careless handling can cause electrocution. Use insulated gloves, tools, and do not wear any metal objects. The same precautions a power-lineman would take. Do not touch any orange high voltage cables. Do not leave key in vehicle, and if it has a smart key, keep it at least 15 feet from vehicle. Do not push vehicle, it could start up and take off. This applies to Toyota’s hybrids but most are somewhat similar. Some differences are Toyota’s hybrids gas engines start up and shut down constantly but Honda’s hybrid gas engine runs full time.