There are many types of cutoff switches, kill switches, dead-man switches... If you have a 2 wire switch whereas having a lanyard yanked off causes the two wires to make contact within the switch... it's simply a matter of having each of those wires connected to one each of the two ignition points. When the lanyard is yanked off, the points are shorted together and that kills the ignition.
The heat sensor TAN wire would lead to one wire of a warning light or horn... the other wire of the light or horn would be connected to the "A" or "I" terminal of the ignition switch as those two terminals have 12v applied ONLY when the key is in the ON or START position.