EN 12515 : 1997

Foreword
0 Introduction
1 Scope
2 Normative references
3 Principles of the method of evaluation
4 Main steps of the calculation
    4.1 General heat balance equation
          4.1.1 Metabolic power (M, in watts per
                  square metre)
          4.1.2 Effective mechanical power (W, in watts
                  per square metre)
          4.1.3 Heat flow by respiratory convection
                  (Cres in watts per square metre)
          4.1.4 Heat flow by respiratory evaporation
                  (Eres' in watts per square metre)
          4.1.5 Heat flow by conduction (K, in watts per
                  square metre)
          4.1.6 Heat flow by convection at the skin
                  surface (C, in watts per square metre)
          4.1.7 Heat flow by radiation at the surface of
                  the skin (R, in watts per square metre)
          4.1.8 Heat flow by evaporation at the skin
                  (E, in watts per square metre)
          4.1.9 Heat storage (S, in watts per square metre)
    4.2 Calculation of the required evaporation rate, the
          required skin wettedness and the required sweat
          rate
5 Interpretation of required sweat rate
    5.1 Basis of the method of interpretation
    5.2 Analysis of the work situation
    5.3 Determination of allowable exposure time (DLE, min)
    5.4 Organization of work in the heat
Annex A (informative) Data necessary for the calculation
of thermal balance
Annex B (informative) Estimation of thermal insulation of
clothing ensembles
Annex C (informative) Criteria for thermal stress and limit
values for thermal constraint
Annex D (informative) Computer program allowing the
calculation of the required sweat rate and of the allowable
exposure time in any thermal environment
Annex E (informative) A-Deviation: National deviation due
to regulations, the alteration of which is for the time
being outside the competence of the CEN/CENELEC member
Annex ZA (normative) Normative references to international
publications with their relevant European publications

Defines a method of analytical evaluation and interpretation of the thermal stress undergone by a subject in a hot situation. Covers a procedure of calculation of the heat balance in addition to the appropriate sweat rate produced by the human body in order to maintain this balance in equilibrium. Known as the 'required sweat rate'.