Table 1.

Individual messages to each respondent during the two iterations of the Delphi exercise.

1st iteration

“The attached Delphi survey aims to score different criteria for their importance for adopting a thermal indicator to protect individuals who work in the heat. It also aims to uncover other important criteria who were not initially included in our list. The Delphi method is a way of obtaining a collective view from experts about issues where there is no or little definite evidence and where opinion is important. This survey incorporates 12 criteria where you have to score from zero (0) to one hundred (100) based on their importance for adopting a thermal indicator to protect people who work in the heat. It is important to note that although you can score a single item with one hundred (100) points, the total score of all criteria should not exceed one hundred (100), which means that, in this case, the remaining 11 criteria should be scored with zero (0). The idea behind this, is that you should distribute one hundred score points among all 12 criteria. If you feel that an item is not important at all, please insert zero (0).” Please note that the Delphi survey incorporates the following item, allowing you to add other important criteria that had not been considered: “If you feel that there are other important criteria that have not been considered, please list them here and insert a relevant score.”

2nd iteration

“Following the completion of the 1st iteration of the Delphi survey that you completed a few weeks ago, please find attached here the 2nd iteration. Once again, I would be grateful if you could complete the survey keeping in mind that this 2nd iteration includes the following two important differences: 1. Next to each item, you will find the mean and the standard deviation of the score from the 1st iteration, which was completed by 20 evaluators who are all experts in environmental physiology, and/or biometeorology, and/or thermal modelling, and/or occupational health policy. 2. Below the initial 12 criteria, you will find five more criteria that were suggested by experts during the 1st iteration of the Delphi survey. If you feel that these criteria are important for adopting a thermal indicator to protect individuals who work in the heat, please score them accordingly. As in the 1st iteration, please keep in mind that the total score of all criteria should not exceed one hundred (100).”