A portable data terminal that includes a housing and an environmentally responsive device for collecting data about the environment surrounding the housing. The portable data terminal also includes an encoded information reader unit with one or more data collection hardware devices, which can capture data encoded in decodable indicia, e.g., bar codes. In one embodiment, the portable data terminal is configured to operate in a mode that processes the decodable indicia, and the environmental data so as to correlate the information decoded in the decodable indicia with the environmental data.