Does Heating Up A PTFE Non-Stick Pan Create "Fumes"?
PTFE (Also known by Dupont's trade name, teflon) can decompose.  For this reason PTFE pans are not recommended for broiler use.  Per the Dupont Key Safety Questions:


  At high temperatures, the quality of the coating may begin to
  deteriorate — it may discolor or lose its nonstick quality. This can
  begin to occur at temperatures above 500°F (260°C). If heated to an
  extremely high temperature, the coating may begin to decompose and
  give off fumes. Fats, butter, or cooking oil will begin to scorch and
  smoke at about 400°F (204°C). DuPont nonstick coatings will not begin
  to significantly decompose until temperatures exceed about 660°F
  (349°C) — well above the smoke point for cooking oil, fats or butter.
  It is therefore unlikely that decomposition temperatures for nonstick
  cookware would be reached while cooking without burning food to an
  inedible state.


Note that even heating a pan completely empty on a high flame will take some time to achieve these temperatures, so if you exercise even a reasonable level of care, you are extremely unlikely to have this occur.