Background
Methods
Participants
Sample size calculation
Study design and setting
Measurement instruments
Index development
Statistical analyses
Results
Variable | Range | Mean | Standard deviation | |
---|---|---|---|---|
Personal factors | Age (year) | 22.00–55.00 | 36.62 | 8.24 |
Body mass index (kg/m2) | 19.23–34.94 | 26.06 | 4.07 | |
Maximum aerobic capacity (ml/(kg·min)) | 29.30–44.16 | 36.16 | 3.20 | |
Body surface area (m2) | 1.64–2.47 | 1.96 | 0.17 | |
Main factors | Dry temperature (°C) | 21.97–48.20 | 24.78 | 6.01 |
Wet temperature (°C) | 12.10–37.57 | 22.01 | 6.60 | |
Globe temperature (°C) | 23.40–62.43 | 39.89 | 9.73 | |
Wind speed (m/s) | 0.00–4.20 | 0.58 | 0.39 | |
Total metabolism (watts) | 130.00–490.00 | 248.47 | 103.70 | |
Clothing thermal resistance (clo) | 0.50–1.35 | 0.83 | 0.14 | |
Physiological parameters | Resting tympanic temperature (°C) | 36.70–37.40 | 37.01 | 0.15 |
Working tympanic temperature (°C) | 36.70–39.10 | 37.70 | 0.56 | |
Resting heart rate (beat/min) | 64.00–94.00 | 76.14 | 5.99 | |
Working heart rate (beat/min) | 70.00–189.00 | 1.21 | 28.45 |
Variable | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
---|---|---|---|---|---|---|---|---|---|---|---|
Age | – | ||||||||||
Body mass index | 0.242** | – | |||||||||
Maximum aerobic capacity | −0.515** | −0.497** | – | ||||||||
Body surface area | 0.060 | 0.817** | −0.327** | – | |||||||
Dry temperature | −0.019 | 0.093 | −0.211** | 0.049 | – | ||||||
Wet temperature | 0.010 | −.027 | −0.172* | −0.065 | 0.626** | – | |||||
Globe temperature | 0.009 | 0.082 | −0.151* | 0.056 | 0.907** | 0.511** | – | ||||
Wind speed | 0.014 | 0.051 | −0.107 | 0.068 | 0.296** | 0.152* | 0.347** | – | |||
Total metabolism | −0.026 | 0.060 | −0.085 | 0.004 | 0.318** | 0.131 | 0.332** | 0.082 | – | ||
Clothing thermal insulation | −0.102 | 0.017 | −0.036 | 0.048 | 0.454** | 0.054 | 0.530** | 0.135 | 0.321** | – | |
Tympanic temperature | 0.139* | 0.177* | 0.350** | 0.101 | 0.751** | 0.685** | 0.766** | 0.258** | 0.509** | 0.388** | – |
Variable | Direct effect | Indirect effect | P value | |
---|---|---|---|---|
Personal factors | Age | 0.226 | 0.031 | P < 0.001 |
Body mass index | 1.057 | 0.145 | P < 0.001 | |
Maximum aerobic capacity | −0.466 | − 0.064 | P < 0.001 | |
Body surface area | 0.775 | 0.106 | P < 0.001 | |
Thermal strain | 0.137 | – | P < 0.001 | |
Main factors | Dry temperature | 0.936 | 0.739 | P < 0.001 |
Wet temperature | 0.872 | 0.688 | P < 0.001 | |
Globe temperature | 0.969 | 0.765 | P < 0.001 | |
Wind speed | 0.311 | 0.245 | P < 0.001 | |
Total metabolism | 0.611 | 0.482 | P < 0.001 | |
Clothing thermal insulation | 0.485 | 0.383 | P < 0.001 | |
Thermal strain | 0.789 | – | P < 0.001 |
Index | Name | Threshold of Fitness | Obtained value |
---|---|---|---|
Absolute fitness indices | Goodness-of-fit index (GFI) | > 0.9 | 0.967 |
Adjusted goodness-of-fit index (AGFI) | > 0.9 | 0.920 | |
Comparative fitness indices | Normed fit index (NFI) | > 0.9 | 0.971 |
Comparative fit index (CFI) | > 0.9 | 0.991 | |
Incremental fit index (IFI) | 0–1 | 0.991 | |
Normed fit index | Root mean squared error of approximation (RMSEA) | < 0.1 | 0.046 |
Normed chi-square (CMIN/DF) | 1–3 | 1.425 | |
P value | > 0.05 | 0.071 |