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