One exercise I recall being driven to a lonely hut on teh airfield and each of us issued with felt tipped pen - one and polos packet - one. These were to signify a combopen and nerve agent pre-treatment tablets. At regular intervals the tannoy would instruct us to take a nerve agetn pre-treatment, but just one mind or you could overdose. If we were subject to an NBC attack and determined we had the symptoms of poisoning we were to inject ourselves with the pen...