In the very cold weather, it is permitted to have a non-Jew light a fire on Shabbos for warmth.  (Shulchan Aruch, Orach Chaim 276:5) However, today, one usually uses a time switch for this purpose, but according to a minority opinion, one should not use a time switch on Shabbos, (except possibly for lights). What is preferable in this particular case for a person who follows the opinion of not using a time switch – to have a non-Jew to light the fire or use a time switch?

There is something which is permitted on Shabbos and Yom Tov, but is forbidden on Chol Hamoed, namely having a non-Jewish contractor build a house for a Jew outside the techum. For a number of reasons, including “maris ayin” one may not employ non-Jewish workers to do work for a Jew on Shabbos, Yom-Tov and Chol Hamoed. Since one may not go outside the techum on Shabbos and Yom Tov, the question of “maris ayin” when a non-Jewish contractor builds a house for a Jew on Shabbos and Yom Tov outside the techum does not apply. However, since on Chol Hamoed, one may leave the techum, a Jew may not employ a non-Jewish contractor to build a house outside the techum on Chol Hamoed. (Shulchan Aruch, Orach Chaim 543:2, Mishnah Berurah 543:4)