This will allow {HEAD ~ people} to work safely in difficult circumstances, such as in polluted air or {TAIL ~ extreme cold}, etc 
This will allow { HEAD ~ people } to work safely in difficult circumstances , such as in polluted air or { TAIL ~ extreme cold } , etc
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH