Figure 1Average daily maximum temperature (℃) during the surveillance period (June 1, 2012 to August 31, 2012). 1Heat wave period: July 22 to August 11, 2012.
Figure 2Scatter plots and graphs of piecewise linear model of number of total heat-related patients according to several temperature indices (A, maximum temperature [℃]; B, maximum heat index [℃]; and C, average temperature [℃]) and threshold temperature (℃). RR, relative risk; CI, confidence interval; AIC, Akaike's information criterion.
Table 1.General characteristics of heat-related patients (n=975)
|
|
n (%) |
Mean |
Minimum |
Maximum |
SD |
Age (y) |
Total |
975 (100) |
52.24 |
4 |
93 |
20.929 |
|
0-19 |
80 (8.2) |
14.68 |
4 |
19 |
3.628 |
|
20-64 |
578 (59.3) |
44.45 |
20 |
64 |
12.094 |
|
65- |
317 (32.5) |
75.91 |
65 |
93 |
7.023 |
Gender |
Men |
676 (69.3) |
- |
- |
- |
- |
|
Women |
299 (30.7) |
- |
- |
- |
- |
Region |
Metropolitan cities1
|
326 (33.4) |
- |
- |
- |
- |
|
Provinces2
|
649 (66.6) |
- |
- |
- |
- |
Location |
Home |
99 (10.2) |
- |
- |
- |
- |
|
Workplace-indoor |
74 (7.6) |
- |
- |
- |
- |
|
Workplace-outdoor |
219 (22.5) |
- |
- |
- |
- |
|
Road |
151 (15.5) |
- |
- |
- |
- |
|
Fields and paddies |
151 (15.5) |
- |
- |
- |
- |
|
Greenhouse |
16 (1.6) |
- |
- |
- |
- |
|
Other-indoors |
37 (3.8) |
- |
- |
- |
- |
|
Other-outdoors |
228 (23.4) |
- |
- |
- |
- |
|
Heat cramp |
123 (12.6) |
- |
- |
- |
- |
Diagnosis |
Heat edema |
2 (0.2) |
- |
- |
- |
- |
|
Heat syncope |
50 (15.4) |
- |
- |
- |
- |
|
Heat exhaustion |
386 (39.6) |
- |
- |
- |
- |
|
Heat stroke |
314 (32.2) |
- |
- |
- |
- |
|
Death |
15 (1.5) |
- |
- |
- |
- |
Outcome |
Admission (ICU) |
86 (8.8) |
- |
- |
- |
- |
|
Admission (general ward) |
171 (17.5) |
- |
- |
- |
- |
|
Transferred |
46 (4.7) |
- |
- |
- |
- |
|
Discharged |
654 (67.1) |
- |
- |
- |
- |
|
Discharged with-out treatment |
3 (0.3) |
- |
- |
- |
- |
Body temperature (°C) |
37.67 |
34.9 |
43.2 |
1.655 |
Systolic blood pressure (mmHg) |
125.25 |
40 |
214 |
24.761 |
Diastolic blood pressure (mmHg) |
76.80 |
28 |
160 |
15.602 |
Table 2.Threshold temperature (°C) and relative risk of heat-related illness associated with 1°C increment of maximum temperature above threshold according to gender, age, diagnosis, and region
|
Latitude1
|
Threshold (°C) |
RR |
95% CI |
p-value |
Gender |
|
|
|
|
|
Men |
- |
31.1 |
1.643 |
1.587, 1.701 |
<0.001 |
Women |
- |
31.6 |
1.822 |
1.716, 1.934 |
<0.001 |
Age (y) |
|
|
|
|
|
0-19 |
- |
31.3 |
1.590 |
1.442, 1.753 |
<0.001 |
20-64 |
- |
30.7 |
1.627 |
1.568, 1.689 |
<0.001 |
65- |
- |
31.8 |
1.863 |
1.755, 1.978 |
<0.001 |
Heat-related illness |
|
|
|
|
|
Mild2
|
- |
31.2 |
1.647 |
1.559, 1.740 |
<0.001 |
Heat exhaustion |
- |
31.1 |
1.666 |
1.589, 1.746 |
<0.001 |
Heat stroke |
- |
31.3 |
1.770 |
1.674, 1.872 |
<0.001 |
Metropolitan cities |
|
32.2 |
1.704 |
1.618, 1.794 |
<0.001 |
Seoul |
37˚34´ |
33.9 |
1.915 |
1.751, 2.094 |
<0.001 |
Incheon |
37˚28´ |
33.8 |
1.725 |
1.500, 1.984 |
<0.001 |
Daejeon |
36˚22´ |
31.4 |
1.675 |
1.434, 1.957 |
<0.001 |
Daegu |
35˚53´ |
33.9 |
1.583 |
1.375, 1.823 |
<0.001 |
Ulsan |
35˚33´ |
33.6 |
1.329 |
1.165, 1.517 |
<0.001 |
Gwangju |
35˚10´ |
32.8 |
1.531 |
1.336, 1.754 |
<0.001 |
Busan |
35˚06´ |
33.1 |
1.610 |
1.381, 1.876 |
<0.001 |
Provinces |
|
30.5 |
1.687 |
1.626, 1.751 |
<0.001 |
Gangwon |
37˚54´ |
28.8 |
1.527 |
1.326, 1.757 |
<0.001 |
Gyeonggi |
37˚16´ |
31.9 |
1.799 |
1.658, 1.953 |
<0.001 |
Chungbuk |
36˚38´ |
30.9 |
1.655 |
1.470, 1.863 |
<0.001 |
Chungnam |
36˚22´ |
34.0 |
1.706 |
1.552, 1.876 |
<0.001 |
Gyeongbuk |
35˚53´ |
31.4 |
1.663 |
1.483, 1.865 |
<0.001 |
Jeonbuk |
35˚49´ |
31.8 |
1.672 |
1.476, 1.894 |
<0.001 |
Gyeongnam |
35˚10´ |
31.3 |
1.678 |
1.496, 1.883 |
<0.001 |
Jeonnam |
35˚10´ |
30.0 |
1.698 |
1.569, 1.837 |
<0.001 |
Jeju |
33˚30´ |
29.6 |
1.803 |
1.375, 2.364 |
<0.001 |
Table 3.Number of patients with heat-related illnesses according to gender, age, and region
Variables |
No. of cases of mild heat- related illnesses (%) |
No. of cases of heat exhaustion (%) |
No. of cases of heat stroke (%) |
p-value1
|
Gender |
|
|
|
|
Men |
200 (29.6) |
272 (40.2) |
204 (30.2) |
0.10 |
Women |
75 (25.1) |
114 (38.1) |
110 (36.8) |
|
Age (y) |
|
|
|
|
0-19 |
20 (25.0) |
40 (50.0) |
20 (25.0) |
<0.001 |
20-64 |
166 (28.7) |
262 (45.3) |
150 (26.0) |
|
65- |
89 (28.1) |
84 (26.5) |
144 (45.4) |
|
Region |
|
|
|
|
Metropolitan cities2
|
87 (26.7) |
111 (34.0) |
128 (39.3) |
0.63 |
Provinces3
|
188 (29.0) |
203 (31.3) |
258 (39.8) |
|