From: Rabbi Moshe Sofer
To: Rabbi Lipman
Rabbi Lipman poses analytical questions about whether Shabbos violations for pikuach nefesh are classified as hutrah (fully suspended) or dechuyah (merely overridden). The Chasam Sofer offers a novel insight that dechuyah can actually be more flexible than hutrah regarding extending the override to additional activities.
Source: Shu"t Chasam Sofer OC §85