code: def apparent_temp(temp, rh, wind):
      
      if temp is None or rh is None or wind is None:
          return None
      vap_press = (float(rh) / 100.0) * 6.105 * math.exp(
          17.27 * temp / (237.7 + temp))
      return temp + (0.33 * vap_press) - (0.70 * wind) - 4.00
docs: Compute apparent temperature (real feel), using formula from
      http://www.bom.gov.au/info/thermal_stress/