As we have seen (above, 25:1), a Jew who performs melakha on Shabbat violates Torah law, whereas a Jew who asks a non-Jew to perform melakha for him violates rabbinic law. Similarly, a minor who performs melakha on Shabbat only transgresses rabbinically (above, 24:1). Consequently, it would seem, at first glance, that when it is necessary to do melakha in order to save a sick person, it is preferable to ask a non-Jew or a child to do it, thereby minimizing Shabbat desecration. However, the Sages stated: “These things should not be done by non-Jews or children, but rather by adult Jews” (Yoma 84b; SA 328:12). This means that even if a non-Jew or a child is present, one should not ask him to do the melakha. Only an adult Jew should do it. Rishonim offer two possible explanations for this rule. First, it is possible that a non-Jew or a child will hesitate and not act aggressively enough to help the sick person (Tosafot). Second, even when it is clear that they will act aggressively enough, we are concerned that those present might incorrectly conclude that an adult Jew may not desecrate Shabbat in order to help someone who is dangerously ill. Then, if faced with a similar situation sometime in the future, they might delay helping in order to look for a non-Jew or a child. In the meantime, the sick person might die (Ran).
Therefore, the Rishonim write that if many people are available to help the sick person, it is a mitzva for the most respected person present to do so, thus making it clear to everyone that saving a life overrides Shabbat and that there is no need to seek ways to minimize the melakha (Ri’az; Tashbetz; MB 328:34).
If the situation is less pressured, and it is easy to find a non-Jew or a child to do the necessary melakhot, and doing so will not cause any delay, then even though le-khatĥila an adult Jew may do whatever melakha is necessary to save a life, it is optimal greater enhancement to minimize Shabbat desecration by having a non-Jew or a child perform the melakhot (SSK 38:2). However, if there is even the slightest, tiniest shadow of a doubt that using a non-Jew or a child will delay the provision of lifesaving treatment, either now or in the future, it is better for an adult Jew to do the melakha.