The apparatus is equipped with cover unit fixed to a head portion of worker so as to cover at least the regions of nose and mouth of the worker, the cover unit capable of trapping the worker’s breath. The heads up display is configured to be worn on the user’s head and display an image within the user’s field of view. In particular embodiments, engineered immunoresponsive cells are antigen-directed and resist immunosuppression andor have enhances immune-activating properties. Where the boiler tube wall panel includes a membrane between tubes, the membrane may be beveled. A Dynamic Object Model includes a software environment front end program component and a hardware environment back end program component.