The talmud tells us that even if the eighth day after birth is Shabbat,
we perform circumcision rather than waiting a day. There is then a
discussion of implementation details (e.g. you still have to prepare
certain things before Shabbat to limit the violations).
On today's daf Abaye repeats several things about infants that he
learned from his mother (who is credited but not named), including:
If an infant cannot suck this is because his lips are cold, and the remedy
is to hold a vessel of burning coals near his nostrils to heat him up.
If an infant does not breathe he should be fanned with a fan and he
will start. If an infant is too red, it means his blood isn't absorbed
in him and it is not safe to perform the circumcision; if he is green
then he is deficient in blood and we wait until he is not. (134a)
Apropos of nothing: have you ever wondered what Judaism has to say about
surviving the
zombie apocalypse? In other words, the season of Purim Torah is
upon us at Mi Yodeya; take a look. (For more in this vein, click on the
purim-torah tag at the bottom of the question.)