Responsa for Shabbat 144:3
אמר מר חומר שבת משאר מצות שהשבת עשה שתים בהעלם אחד חייב על כל אחת ואחת מה שאין כן בשאר מצות היכי דמי אילימא דעבד קצירה וטחינה דכוותה גבי שאר מצות אכל חלב ודם הכא תרתי מיחייב והכא תרתי מיחייב אלא שאר מצות דלא מיחייב אלא חדא היכי דמי דאכל חלב וחלב דכוותה גבי שבת דעבד קצירה וקצירה הכא חדא מיחייב והכא חדא מיחייב
Abaye maintained: He is culpable, since he had the intention of cutting in general.<span class="x" onmousemove="('comment',' Whereas to avoid culpability he must have had no intention of cutting at all. ');"><sup>5</sup></span> Raba said, How do I know it? Because it was taught: [In one respect] the Sabbath is more stringent than other precepts; [in another respect] other precepts are more stringent than the Sabbath. The Sabbath is more stringent than other precepts in that if one performs two [labours] in one state of unawareness, he is culpable on account of each separately; this is not so in the case of other precepts. Other precepts are more stringent than the Sabbath, for in their case if an injunction is unwittingly and unintentionally violated, atonement must be made: this is not so with respect to the Sabbath.
Maharach Or Zarua Responsa
R. Hayyim Eliezer recalls that one time, the winterhouse was once heated by a Gentile on the Sabbath, and his father refused to eat therein. R. Samuel of Falaise in the name of R. Yom Tov permitted one to dwell in a winterhouse that was warmed by a Gentile on the Sabbath. In our city, most of the people rely upon this decision and dwell in winterhouses that are warmed by Gentiles on the Sabbath.