Click this link to view O*NET’s Work Context section for Heating and Air Conditioning Mechanics and Installers. Note that common contexts are listed toward the top, and less common contexts are listed toward the bottom. According to O*NET, what are some common work contexts for Heating and Air Conditioning Mechanics and Installers? Check all that apply. Deal with physically aggressive people face-to-face discussions exposed to disease or infections freedom to make decisions telephone exposed to contaminants.