Table 3.
Complete list of interventions evaluated by effectiveness, cost, feasibility and sustainability
| Intervention | Strength of evidence | Effectiveness (best/ (worst) scenario) | Cost (considering acquisition and operation) | Feasibility (indoor/ small spaces | Feasibility (outdoor/ open spaces) | Environmental impact (ecological foot print) |
|---|---|---|---|---|---|---|
| Environmental conditioning | ||||||
| Air conditioning | 2 | 3.0 / (0.75) | HIGH | −0.8 | −2.9 | HIGH |
| Misting fan | 2 | 2.5 / (1.4) | MOD | −1 | −1.8 | MOD |
| Fanning | 3 | 2.4 / (1.2) | MOD | −0.8 | −1.9 | MOD |
| Shading | 1 | 2.3 / (0.6) | LOW | −0.7 | −1.3 | LOW |
| Clothing | ||||||
| Air cooled garments | 3 | 3.0 / (2.3) | HIGH | −2 | − 2.6 | HIGH |
| Liquid cooled garments | 3 | 3.0 / (2.3) | HIGH | −2.3 | −3 | HIGH |
| Cooling vest | 3 | 1.7 / (1.7) | MOD | −1.3 | −2 | MOD |
| Elevated design clothing | 1 | 1.2 / (1.2) | MOD | −1.4 | − 1.7 | MOD |
| Ventilator-incorporated clothing | 1 | 1.1 / (1.1) | MOD | −1.8 | − 1.8 | MOD |
| Compression garments | 3 | 1.0 / (0.8) | MOD | −1.3 | −1.6 | LOW |
| Protective clothing | 2 | 0.7 / (0.6) | MOD | −1.6 | − 1.7 | LOW |
| Innate conditioning | ||||||
| Short term HA | 3 | 1.9 / (1.8) | NONE | −1.7 | −1 | NONE |
| Medium term HA | 3 | 2.5 / (2.4) | NONE | −1.4 | −0.9 | NONE |
| Long term HA | 3 | 2.9 / (2.6) | NONE | −1.6 | − 1.1 | NONE |
| Aerobic fitness | 3 | 2.9 / (2.1) | NONE | −1.2 | −1.0 | NONE |
| Personal cooling solutions | ||||||
| Cold water immersion | 3 | 2.2 / (1.9) | MOD | −1.6 | −1.9 | LOW |
| Intravenous cooling | 2 | 2.3 / (1.7) | HIGH | −2.3 | −2.6 | MOD |
| Cold air inhalation | 2 | 2.1 / (1.2) | HIGH | −2.1 | −2.5 | MOD |
| Cold fluid ingestion | 3 | 2.0 / (1.7) | MOD | −1.3 | −1.5 | LOW |
| Cooling packs | 3 | 1.8 / (1.5) | MOD | −1.6 | −2.1 | MOD |
| Skin wetting | 3 | 1.7 / (1.4) | LOW | −1.9 | −1.6 | LOW |
| Neck/head cooling | 3 | 1.2 / (1.1) | MOD | −1.7 | − 1.5 | LOW |
| Ice towels | 2 | 1.5 / (1.3) | MOD | −2.2 | −1.9 | LOW |
| Cooling glove | 2 | 0.8 / (0.6) | MOD | −1.8 | −2.2 | MOD |
| External menthol use | 3 | 0.7 / (0.3) | LOW | −2 | −1.9 | LOW |
| CInternal menthol use | 3 | 0.7 / (0.3) | LOW | −1.8 | − 1.7 | LOW |
| Pacing | ||||||
| Change in work schedule | 0 | 2.0 / (1.5) | NONE | −1.5 | −1.6 | NONE |
| Work intensity reduction | 1 | 1.8 / (1.8) | NONE | −1 | −1.1 | NONE |
| Breaks | 1 | 1.3 / (1.3) | NONE | −1 | −1.1 | NONE |
| Hydration and nutrition | ||||||
| Hydration | 3 | 2.0 / (2.0) | LOW | −1 | −0.9 | NONE |
| Electrolyte consumption | 1 | 1.2 / (0.9) | LOW | −0.7 | −0.6 | NONE |
| Carbohydrate ingestion | 2 | 0.6 / (0.6) | LOW | −0.7 | −0.6 | LOW |
| Protein ingestion | 2 | 0.3 / (0.3) | LOW | −0.7 | − 0.6 | LOW |
Table 3 is a summary table of all the identified available solutions to mitigate occupational heat strain, which have been evaluated on four-point scales for five different criteria: the strength of evidence in the literature, the proven effectiveness of the method in best (bolded numbers) and worst case (numbers in parentheses) scenarios, the cost, the feasibility (separated into indoors and outdoors) and the environmental impact. Scores for strength of evidence were: 0, expert knowledge or non-human based research; 1, original research; 2, systematically reviewed but not meta-analysed; and 3, systematically reviewed and meta-analysed. Effectiveness scores were: 0, ineffective or detrimental; 1, slightly beneficial; 2, moderately beneficial; and 3, beneficial. Cost evaluations were: none, low, moderate (MOD) and high. Feasibility scores were: 0, no disruptions to normal work; − 1, minor interruptions; −2, moderate interruptions; and − 3, major interruptions. Environmental impact scores were: none, low, moderate (MOD) and high.