Dry ice sublimates and releases CO₂. Levels can rise in an enclosed space depending on quantity and air exchange; smell cannot tell you the atmosphere is safe.
Assess the vehicle with a competent safety professional: where the driver sits, where the load is, how air is exchanged and where monitoring is needed. Write alarm, evacuation and re-entry steps using maker and workplace guidance.
On alarm or symptoms, leave the area, prevent entry and call emergency support. Do not re-enter an enclosed space until monitoring confirms it is safe.
