Table 1.

Classification of heat wave (HW) days, risk assignments, and definition of Difference-in-Differences.

	Temperature Monitoring Data		Change
	Heat Wave Days	Non-Heat Wave Days
HW alert +	E[Y1(1)]	E[Y0(1)]	E[Y1(1) − Y0(1))
HW alert −	E[Y1(0)]	E[Y0(0)]	E[Y1(0) − Y0(0)]
Difference	E[Y1(1) − Y1(0)]	E[Y0(1) − Y0(0)]	Δ= E[Y1(1) − Y1(0)] − E[Y0(1)−Y0(0)]