Q. (See question 1098 above, in regards to turning off the AC when it is too cold.) Is it better if I tell one Goy to tell another Goy?

A. Mishna Berura (307: 24) quotes several opinions that permit telling one Gentile to instruct another one (amira l’amira) to do a melacha on Shabbos (Chavas Yair 53, Chasam Sofer O.H. 60.) However, Mishna Berura (ibid.) and Biur Halocho (ibid. d’h Veafilu) rule to be stringent unless there is great necessity. Shemiras Shabbos Kechilchoso (30: n 51) quotes also different opinions whether it makes a difference if the second Gentile does not know that he is performing work for a Jew and he thinks it is for the sake on the Non- Jew.
Horav Shlomo Miller’s Shlit’a opinion is similarly to be stringent. He maintains that this “heter” of “amira l’amira” should not be used by itself, only to be added to other significant reasons to be lenient and when there is great need. In our particular case, there may be some benefit to turn off the A.C. by using “ amira l’amira”

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a