There are three distinct types of muscles: skeletal muscles, cardiac or heart muscles, and smooth (non-striated) muscles.
HVAC technicians are responsible for the installation, maintenance and repair of heating, ventilation and air conditioning (HVAC) systems. As an HVAC technician, your job duties may include inspecting existing systems and making recommendations intended to improve the efficiency and/or safety of that system's performance. HVAC-R techs may also work on refrigeration systems.
A majority worked for plumbing, air conditioning and heating contractors. A few were self employed. Most jobs were full time and, during busy times of the year overtime is usually required. Working as an HVAC technician can be uncomfortable or even dangerous.