According to Mori V'Rabi

 

According to Mori V'Rabi Harav Hagaon R. Shlomo Miller Shlita  1)  Having a Goy push a wheelchair or a baby carriage in a רשות הרבים since their handles are above 10 טפחים, it is considered a שבות דשבות. 2) The היתר of שבות דשבות (even במקום מצוה) is not always applicable a Rav needs to be consulted. 3) At Outdoor Minyanim you may not have a Goy turn on the propane heater on Shabbos.