As a first responder, strong consideration should be given to calling local hospitals to see if additional casualties with similar symptoms have been observed. Casualties may occur hours to days or weeks after an incident has occurred. The time required before symptoms are observed is dependent on the radioactive material used and the dose received. Additional symptoms include skin reddening and, in severe cases, vomiting.

Containers may display a radiation symbol.

Material that seems to emit heat without any sign of external heating source.

If the material is strongly radioactive, it may appear to glow.