90:18 When it’s (very – OC 276:5) cold out, one may ask a non-Jew to turn on the heat because, when it comes to the cold, everyone is considered potentially sick. However, one should not do this if it’s not actually necessary. One may not allow a non-Jew to re-heat the house on Shabbos afternoon so that it will be warm on Saturday night.
90:19 One may not send a non-Jew beyond the Shabbos boundary in order to notify relatives that someone has died or to tell them to come to deliver a eulogy. (One may instruct him on Shabbos to go after Shabbos because this is for the purpose of a mitzvah – Mishnah Brurah 306:40; see above, 90:14).