deliverable 3.0. : report on safety criteria and predictors

Authors : Victoria Richmond and George Havenith

Rationale

The purpose of this review was to discuss safety criteria for heat exposure and available predictors for monitoring heat strain.  Using the information gathered in this review, the following paragraphs summarise the main considerations in answering these questions and suggest appropriate ways forward.

Methods

A literature review and existing expertise was used to answer the following questions: 1) ’what is a safe core body temperature (T_c) limit for working in the heat?’ taking into consideration all the parameters which might affect the critical T_c of these individuals including acclimatisation, aerobic fitness and clothing; 2) ’what are the working conditions that may limit or improve the critical T_c?’ can the workers gain quick access to cooling facilities, or will it take time to remove PPE and implement cooling strategies?

Results

Selecting a measure or predictor to monitor T_c brings with it many confounding factors.  The direct measures of T_c are unlikely to be accepted due to their invasive nature, while indirect measures tend to have poor reliability.  The alternative is to predict T_c from one or more physiological parameters which reflect heat strain.  Following a review of the literature, possible measures which could be combined include skin temperature (T_s), insulated skin temperature (T_is), respiratory rate, heart rate and heat flux.

Applicability

The results of the literature review will be used in the Prospie project to identify potential measures for monitoring T_c; as well as defining the T_c limits that will be used to warn workers and yield central warnings when necessary. Once the measurement technique and safe T_c limit have been defined, the ’cut-off’ T_c must be determined, taking into consideration the number of workers who should be protected and the error in the measurement.