Which risk does shaving a patient's chest hair before defibrillation mitigate?

Shaving a patient's chest hair before defibrillation primarily mitigates the risk of electrical arcs leading to a fire hazard. When defibrillator pads are applied over hairy skin, the presence of hair can create a barrier that may prevent good electrical contact between the pads and the skin. This poor contact can lead to imperfect energy transfer, resulting in arcing of electricity through the hair instead of direct contact with the skin. Such arcs carry the potential to ignite any flammable materials or substances nearby, creating a serious fire hazard during a critical medical procedure. Thus, ensuring a clean surface through shaving helps enhance electrical conductivity and patient safety during defibrillation.