Q. When did the Church start celebrating Mass daily?
There are certain practices that are so intrinsic to the exercise of our Catholic faith that people assume that they were in existence in every age and every place from the very beginning. This is often not the case. Daily Mass and a great many other Catholic observances that are now a huge part of the devotional life of the faithful have come to us through a gradual and organic evolution.
Q: Does the Church provide guidelines for what a priest and congregation should do in the case of a medical emergency taking place during Mass?
After 2,000 years, the Church has experienced just about everything. It should, therefore, come as no surprise that, having been through this before, she has a contingency plan to deal with what you're describing. There are many ways, however, in which the Mass can be interrupted, so let's talk about them all.