Wiring an emergency shutoff
The emergency latching push button switch, also known as a mushroom push button switch (Pilz Schaltgerät), is used to cut off, through it's NC contact, electrical power to a machine / electrical equipment under an emergency situation, to avoid injury to personnel or damage to the equipment.
The mushroom button S0 is released, by rotating it, when the fault is cleared.

To ensure that the equipment does not restart immediately after the mushroom button is released, a 'zero-volt safety' feature is provided.
The 'zero-volt safety' feature ensures equipment restart only after a start button S1 is actuated. This feature also prevents the equipment from automatically restarting after power is restored after a failure. The function is performed by an electromagnetic relay K0. The NO contacts of K0 switch on the power to the equipment.
In equipment where there is a higher risk of injury to personnel, the single relay K0 is replaced by a 'Safety Relay' (Sicherheitsrelais), with dual redundancy, to ensure fail-safe operation.
For your purpose, it would suffice to wire the NO contacts of K0 in the lines powering the circuits of the room.