Ready for an emergency, say

ONCALL

["Think of a doctor or technician who must be available to respond quickly, even outside regular hours. This phrase often describes their status."]

"Ready for an emergency, say" hints at someone who’s available to respond quickly, like a doctor or technician waiting to be called in. The phrase "on call" fits perfectly—it’s a common term for being prepared to act at a moment’s notice. The answer drops the space to become "ONCALL," which is how crosswords often handle multi-word phrases. The "say" in the clue just means it’s one possible example of readiness.