It is MOST important to park your ambulance upwind and uphill of a hazmat incident scene because:
A) If the chemical ignites and explodes, the fallout from the blast will most likely sink into valleys and ditches instead of rising.
B) Hazardous chemicals that turn to gas rarely have a vapor density that is heavier than the air, regardless of the amount of chemical.
C) The risk of being contaminated is minimal if the chemical travels, and you will have greater visibility of the entire incident scene.
D) The vapor density of many chemicals is less than that of the air, causing the vapor to rise and dissipate as it travels with the wind.