2007, Piran, Slovenia

Environmental Ergonomics XII
Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007
COMPUTER APPLICATION FOR THERMAL RISK AND
DISCOMFORT ASSESSMENT IN COLD WORKPLACES
Pilar Armendáriz Pérez de Ciriza and Eduardo Gil Iglesias
National Institute for Safety and Hygiene at Work, Ministry of Labour and Social Affaires,
Madrid, Spain
Contact person: parmenda@mtas.es
INTRODUCTION
Occupational exposure to cold environments can result in the loss of body heat that can have
adverse effects on discomfort and health. It may also induce illnesses and injuries related to
the cold, and promote the beginning or the worsening of symptoms associated with certain
illnesses. Cold reduces the manual dexterity, even when gloves are worn, and it disturbs
physical performance. Besides, cold may distract workers and alter behaviour, which may
have unfavourable consequences for safety and productivity.
Among risks derived from cold stress, the risk of hypothermia, or cooling of the body as a
whole, may have worst consequence for workers’ health, because acute hypothermia can lead
to death. Cold stress can increase the risk of cooled tissues of the extremities and face
suffering freezing and lesions of affected parts. Some work in enclosed places, and especially
those that are carried out in cold stores, require cold conditions to be carried performed
correctly. In other cases, such as construction, agriculture, etc. work is performed outdoors,
and therefore workers are exposed to the cold in winter.
METHODS
EVALFRÍO is based on the cold stress assessment methods contained in the Spanish
experimental standard UNE-ENV ISO 11079: 1998 Evaluation of cold environments.
Determination of required clothing isolation (IREQ) (ISO/TR 11079:1993).
The assessment of hypothermia risk is based on a calculation of the body heat exchange and
of the required clothing isolation (IREQ) that worker's clothes should provide for the
maintenance of a thermal equilibrium during the work situation being evaluated. As there is
an upper limit for the amount of isolation clothing can provide, a duration limit exposure
(Dlim) can be calculated for the existing clothing isolation on the basis of acceptable body
cooling as well as the recovery time (RT) that worker should be allowed in a warm place to
restore normal body heat balance.
RESULTS
EVALFRÍO assesses cold risks and discomfort and creates databases with data results or just
assesses cold risks. Occupational preventionists can evaluate risk of hypothermia and cold
discomfort in the body as a whole with the required clothing isolation index (IREQ) and local
cooling risks and discomfort in hands and feet with skin temperature measurements and in
respiratory tract with air temperature measurements, both indoor and outdoor. For outdoors
environments, EVALFRÍO also evaluates convective cooling in bare skin with wind chill
index (WCI) or chill temperature.
DISCUSSION
The computer application EVALFRÍO has been developed as an easy tool to help
occupational practitioners in the assessment of cold stress risks at work, and to provide
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