Content uploaded by Hilde Færevik
Author content
All content in this area was uploaded by Hilde Færevik on Dec 05, 2014
Content may be subject to copyright.
Ambience`14&10i3m, 7-9 Sept 2014 Tampere, Finland
1
CLOTHING AND PROTECTION IN ARCTIC ENVIRONMENTS
H. FÆREVIK1, Ø. WIGGEN1
1SINTEF Technology and Society, Department of Health Research, Trondheim, Norway
hilde.ferevik@sintef.no
Abstract
Increased activity in the Arctic areas promotes the need for improved clothing and protection in this harsh, cold
environment. Work in cold climate represents a threat to human health safety and performance. The risk associated
with work in cold climate ranges from discomfort, reduced muscular and cognitive performance to cold injury and
hypothermia in the long term. Cold climate endanger the heat balance and protective clothing is important to maintain
thermal comfort and reduce heat loss. Cold climate clothing can be bulky and uncomfortable, affecting performance
and increasing muscle strain and work-load. By developing new high-tech clothing, using advanced technologies such
as adaptive temperature and moisture transport, insulation and integration of sensors that can detect critical levels of
cold stress, the comfort, performance and safety of the workers in the Arctic can be improved.
Keywords: Clothing, Protection, Thermoregulation, Arctic, Cold Climate
1 Introduction
In the years ahead, a significant increase in human activity in the Arctic is expected. There is a growing interest in
tourism, increased maritime traffic, and a great potential for industrial development and growth (oil and gas
exploration, fisheries, aquaculture, mining) in the Arctic areas. Arctic is defined as the geographical areas North of the
Polar Circle 66° 33'N. For the Norwegian Government "The High North" is one of Norway’s most important strategic
priority areas [1]. Year-round activity in these areas involves more challenging climatic conditions than in the areas
further south. Unpredictable weather, low sea and air temperatures, strong winds, polar nights, polar lows, long
distances and limited infrastructure pose major challenges with regard to the health, safety and performance of
people working in the Arctic. The potential hazards associated with work in cold climate have led to an increased
awareness and the need to develop preventive measures. Innovative solutions for cold climate clothing and
protection have been put forward as a preventive measure in several central documents [2, 3]. Improved cold weather
protection will ensure that the personnel can execute their work in a safe and efficient manner in the demanding
climatic conditions of the Arctic. This paper will describe some critical factors for work in cold climate, examples of
clothing and protection and give a brief look at recent developments in fabrics and garments for cold protective
clothing.
2 Protection against cold
The effects of cold on human beings are mainly dependent on the four basic environmental variables (air
temperature, wind-speed, precipitation and radiation), the level of activity and the clothing used. Extreme climatic
conditions in the Arctic in combination with other factors (snow, ice, remoteness, darkness, etc.) increase the stress
level and the risk of accidents. Protective clothing and seeking shelter are the most natural means of protecting
oneself against the cold harsh climate in the Arctic. However, cold-weather clothing can be bulky and uncomfortable,
affecting performance and increasing muscle strain and work-load [4]. Cold endangers the body's heat balance and
requires countermeasures (e.g clothing, work-rest schedules/shielding/behavioural actions etc.) to control heat loss.
Depending on the level of cooling (local/whole body), the human response to outdoor cold exposure ranges from
discomfort, reduced muscular and cognitive performance to cold injury and hypothermia in the long term [5]. The
actual risk associated with work in cold climate depends on individual factors (gender, age, health, fitness, degree of
acclimatization, level of experience ect), physical (touching cold objects, icy surfaces, falling ice) and psychosocial
factors (e.g impact of darkness on mood).
Ambience`14&10i3m, 7-9 Sept 2014 Tampere, Finland
2
Prevention of cooling and the maintenance of heat balance are regulated by the heat exchange between the human
body and the environment. Clothing is essential in preventing heat loss from the body in the cold, and this is largely
dependent on the thermal properties (insulation, evaporative-, wind- and water resistance), design and construction
of the clothing (weight, fibres and fabrics, ergonomics). The clothing insulation required for cold protection is
dependent on the activity level of the wearer (the amount of heat generated in the body) and the climatic factors
(which determine the heat loss from the body). International standards have been developed to estimate the needed
level of clothing insulation during different levels of activity and climatic factors and the determination of wind cooling
(risk of frostbite) [6]. The IREQ model allows for a certain reduction in body heat content (144 kJ · m-2), and it is then
possible to calculate the duration limited exposure (DLE). Below is an example of a DLE analysis for three different
cold climate clothing concepts for petroleum workers in the Arctic [5] (Figure 1 and 2). Total clothing insulation for the
three clothing concepts: 1 (1.7 Icl) , 2 (2.2 Icl) and 3 (2.6 Icl). The solid line represents DLEneutral where the thermal strain
is low, while the dashed line represents DLEmin where thermal strain is high (see Figure 1 and 2).
Figure 1 Duration of limited exposure with low (100 W · m-2) work intensity and 5 m/s wind when wearing three
different cold climate clothing concepts for petroleum workers.
Figure 2 Duration of limited exposure with moderate (165 W · m-2) work intensity and 5 m/s wind when wearing three
different cold climate clothing concepts for petroleum workers.
There is a large effect of increased work intensity on the recommended duration of cold exposure. Concept 1 has the
lowest insulation and the shortest allowable time for outdoor work (Figure 1). These results can be used by the
industry as a guideline for selecting appropriate clothing for different ambient temperatures and work tasks to be
performed. It is important to note that at the highest workload, sweat is likely to occur and accumulate in the
clothing, thereby reducing insulation. The IREQ model does not take this into consideration. Therefore, when
developing and selecting appropriate clothing for Arctic conditions, several aspects such as e.g. moisture transport
needs to be considered.
-40
-35
-30
-25
-20
-15
-10
-5
0
01234
Ambient temperature (°C)
Recommended duration limited exposure (h)
Concept 1 DLEmin
Concept 1 DLEneutral
Concept 2 DLEmin
Concept 2 DLEneutral
Concept 3 DLEmin
Concept 3 DLEneutral
-40
-35
-30
-25
-20
-15
-10
-5
0
02468
Ambient temperature (°C)
Recommended duration limited exposure (h)
Concept 1 DLEmin
Concept 1 DLEneutral
Concept 2 DLEmin
Concept 2 DLEneutral
Concept 3 DLEmin
Concept 3 DLEneutral
Ambience`14&10i3m, 7-9 Sept 2014 Tampere, Finland
3
One of the greatest risks when working in a cold climate is the degradation of manual performance. Field studies at
Statoils LNG station at Melkøya outside Hammerfest, Norway demonstrated that fingers and hands are most
vulnerable to cooling, causing a degradation in manual performance [7]. Optimal manual performance is a
prerequisite for performing certain work tasks critical for petroleum workers in the Arctic such as lifting, installation,
handling of tools and working with small screws and bolts. In order to complete the tasks that require fine manual
dexterity, the workers need to remove their gloves to ensure proper task execution. This will lead to a rapid cooling,
resulting in hand and finger temperatures of 15-20 °C, which are critical values of maintaining optimal manual
performance [8]. The work wear used by petroleum workers at Melkøya did not meet the requirements for thermal
protection in order to maintain manual performance over time [9]. Reduced function of both fine and gross manual
dexterity was observed already at an ambient temperature of -5°C. This can result in decreased performance and
increased risk of mistakes. Pre-heating or auxiliary heating can help maintain manual performance during prolonged
periods of cold exposure. Sufficient protection of the hands and the body can counteract the detrimental effects of
cold on manual performance and there is a need for gloves adapted to different working situations.
3 Cold climate clothing for explorers – retrospective perspective
The interest in finding the optimal cold protection is not a novel idea. In their attempt to be the first to reach the
South Pole in 1911, Amundsen and Scott had different strategies for protection from the cold, harsh weather. While
Amundsen relied on fur from reindeer and seal as major insulator in the clothing, Scott used cotton and wool for this
purpose. Havenith benchmarked the functionality of the replica clothing of Amundsen and Scott to modern explorer
clothing in terms of insulation, insulation per weight and wind protection [10]. The modern clothing consisted of man-
made materials such as polyester fleece and down for insulation. Not surprisingly, the modern clothing performs best,
providing highest insulation and best wind protection. The biggest advantage compared to the Scott and Amundsen's
clothing was the lower weight. The study further concluded that the Scott clothing was inferior to the Amundsen’s fur
based clothing and had a lower insulation to mass ratio. Scott's clothing resulted in extra energy usage caused by the
weight of the clothing, bulkiness, friction and stiffness which would have contributed to weakening the Scott team
members. A recent EU project (Safe@Sea) developing new and safer work clothing for fishermen, demonstrated that
use of a lighter and more complaisant fabric in the clothing, combined with good ergonomic design and freedom of
movement will reduce the energy cost by working and sweating, while providing the same level of protection from the
cold [11]. Improved work economy will reduce physiological stress and hence the risks of fatigue.
4 The future of cold protective clothing
The increased interest in extreme leisure activities such as climbing, expeditions, kayaking and diving, have led to a
higher extent of innovative high-tech clothing for use in extreme environments compared to the development seen in
work wear. Man- made materials, new technologies, new design and wear philosophies have been developed to
improve the thermal properties of clothing and protection of the wearer. Traditionally, the main principle of cold
climate clothing concepts have been the three layer system. This consist of an inner layer that controls the
temperature and humidity of the microclimate, a middle layer that provides most of the insulation but also provides
transport of moisture outwards, and the outer layer which provide protection against the outer environment. One
main challenge in the cold is to control temperature and humidity of the clothing during high and low intensity and
varying ambient conditions. Natural fibres like wool are often used in the inner layer garment in the cold because of
the excellent insulation properties and high moisture absorbing capacity, keeping the skin relatively dry even when
sweating. Synthetic fibres are hydrophobic and moist air moves from the skin through the fabric to the next layer.
Cotton has a high wicking effect and is therefore not recommended in the cold. Moisture accumulated in the inner
garment causes discomfort and reduces the insulation. In addition, energy is used to the drying of the wet garment
when activity stops which causes a post-chilling effect. Improved ventilation by moisture management of high-tech
modern fabric is therefore an important factor for performance and thermoregulation in cold environments.
Nanotechnology opens new possibilities, and a new generation of textiles which adapts its insulation and breathability
according to the surrounding environment have been developed. Examples of such technologies are the Schoeller C-
change and the Adaptive moisture management bio-responsive fibres and yarns developed by INOTEK™ textiles LTD
Ambience`14&10i3m, 7-9 Sept 2014 Tampere, Finland
4
[12, 13]. Both technologies refer to the "pine cone effect", where the heat and moisture permeability adapts in
response to humidity changes in the micro-climate of the clothing system. Another example of adaptive materials is
phase change materials (PCM) which consists of paraffin wax that has the ability to store and release latent heat as
the phases change. PCM has the potential to reduce thermal stress and improve thermal comfort when integrated in
clothing, absorbing heat during periods when external heat load exceeds the heat loss and releasing heat when the
process is reversed [14]. New technologies for improved insulation have been developed the recent years. Airvantage®
by Gore-Tex uses air-tubes in the jacket for adjustable insulation [15]. Aerogels® consists of 90% air and 10% silica and
has been tried out as insulator in cold protective clothing [16]. Aerogel has the advantage of being extremely
lightweight while providing high insulation, it is however very brittle and expensive. Integration of sensors in textiles
can provide valuable information about vital physiological parameters and critical levels of cold stress. This was
demonstrated in a working jacket for petroleum's industry with integrated temperature, humidity and activity sensors
[17]. The jacket provides easy accessible information about the thermal conditions at the site of the worker and local
cooling effects of extremities. This information can be used in an enhanced safety perspective as an improved tool to
advice outdoor work control for workers in cold climate. Finally, the most important qualities of cold protective
clothing is to improve the comfort of the wearer by keeping them warm, dry and safe while still being able to ensure
functionality and comfort. This is not possible without an optimal design and involvement of the end-users in the
development process [18].
References
[1] Meld. St. 7 (2011–2012). The High North – Visions and Strategies. Report to the Storting (white paper) Norwegian
Government.
[2] Barents 2020. Assessment of International Standards for Safe Exploration, Production and Transportation of Oil
and Gas in the Barents Sea.
[3] Meld. St 29 (2010-2011) Felles ansvar for eit godt og anstendig arbeidsliv. Ministry of Labour and Social Affairs.
Report to the Storting (white paper).Norwegian Government.
[4] Holmer., I.: Evaluation of cold workplaces: an overview of standards for assessment of cold stress, Ind Health, Vol.
47 (2009), pp. 228-234.
[5] Færevik., H., Sandsund., M., Wiggen. & Ø., Renberg J.: SINTEF report F24656 Arctic weather protection, health
effects, monitoring systems and risk assessment. (2013).
[6] ISO 11079 Ergonomics of the thermal environment — Determination and interpretation of cold stress when using
required clothing insulation (IREQ) and local cooling effects (2007).
[7] Færevik., H.; Tjønnaas.; MS., Heen.; S., Wiggen., Ø. & Reinertsen RE.: Required clothing insulation and
recommended outdoor work exposure time for petroleum workers in the arctic. International Conference of
Environmental Ergonomics Nafplio, Greece 10-15 July 2011.
[8] Heus., R.; Daanen., HA. & Havenith. G: Physiological criteria for functioning of hands in the cold: a review. Appl
Ergon, Vol 26(1995), pp. 5-13.
[9] Wiggen., Ø.; Heen. S.; Færevik. H. & Reinertsen. RE: Effect of cold conditions on manual performance while
wearing petroleum industry protective clothing, Industrial Health, Vol 49(2011), pp. 443–451.
[10] Havenith., G.: Benchmarking functionality of historical cold weather clothing: Robert F. Scott, Roald Amundsen,
George Mallory, Journal of Fiber Bioengineering and Informatics, Vol 3.3(2010), pp.121-129.
[11] Færevik., H.; Wiggen., Ø.; Næsgaard, OP.; Varheenmaa, & Peltonen C.: Safe@Sea. Final report on material and
clothing testing. SINTEF report F24204 (2012).
[12] Available from: http://www.schoeller-textiles.com/en/technologies/c-change.html. Site Accessed: 2014-08-08
[13] Available from: http://www.inotektextiles.com/technology/#pinecone. Site Accessed: 2014-08-08
[14] Reinertsen RE, Færevik H, Holbø K, Nesbakken R, Reitan J, Røyset A, Thi MSL (2008). Optimizing the performance
of phase change material in personal protective clothing systems, Int J Occup Safety Ergonomics, 14, 43-53
[15] Available from: http://www.gore-tex.com.au/airvantage-insulation-technology/w4/i1001292/. Site Accessed:
2014-08-08
[16] Available from: http://www.aerogel.com/markets/outdoor.html. Site Accessed: 2014-08-08
[17] Seeberg., TM.; Vardøy., ASB.; Austad., HO.; Wiggen., O.; Stenersen., HS.; Liverud., AE. & Faerevik H.: Protective
jacket enabling decision support for workers in cold climate, Engineering in Medicine and Biology Society (EMBC),
pp. 6498-6501, Proceedings of the 35th Annual International Conference of the IEEE, Osaka, Japan, 3-7 Juli 2013.
[18] Storholmen., TCB.; Naesgaard., OP.; Faerevik., H.; Reitan., J.; Holmen., IM. & Reinertsen RE.: Design for end-user
acceptance: requirements for work clothing for fishermen in mediterranean and northern fishing grounds.
International maritime health, Vol 63(1) (2012), pp. 32-39.