Tightness of the chest, dim vision and a seriously runny nose, you have been exposed to a nerve agent. If there is an ATROPINE self injector nearby you should immediately self medicate while you have control of your muscle actions.
If not: Sit down in a comfortable position and close your eyes. Death will come quickly. It will be painful, but it will not last long.
Make your peace with God.
I learn something new everday.
Thanks exSoldier.