90:16 If one sees that he may incur a loss, such as if one of his wine barrels is leaking, it is permitted to call a non-Jew to that place even though he knows that the non-Jew will definitely fix it. This is true even with an actual form of labor so long as the Jew does not say any hint to the non-Jew that he should fix it. One may say in the non-Jew’s presence, “Whoever saves me from this loss will not go unrewarded!” (But he may not say directly, “If you protect me from this loss, you will be rewarded” - Mishnah Brurah 307:70.) One should only say this when he is faced with a large loss. (MB 307:71 permits it even in the case of a smaller loss.)
90:17 In order to enable performing a mitzvah or to take care of a person who is slightly sick, one may direct a non-Jew to perform an activity that is not an actual form of labor, but that is only prohibited because of the cessation of labor (shvus). From this we have the practice in places where there is no eiruv to send non-Jews to bring things required for Shabbos. (One may not pay a non-Jew for providing this service – MB 325:61; it is only permitted to send the non-Jew to carry in a carmelis, not in a Biblically-prohibited public domain – Rema 325:10.) This should only be done in an actual case of need, not merely for one’s enjoyment. One may not tell a non-Jew to bring something from outside the Shabbos boundary (techum) and if one does so, he may not use the object that the non-Jew brought until after Shabbos. Some authorities say that one may allow a non-Jew to do such things when one is faced with the possibility of a financial loss. For example, one may permit a non-Jew to move merchandise that would be ruined by the rain. The Kitzur Shulchan Aruch says that one may rely on this opinion when faced with a large potential loss.