Regional thermal sensitivity to cold at rest and during exercise

Thermal sensitivity has been of scientific interest for almost a century. Despite this, several research questions within this field remain unanswered, particularly regarding the specific distribution of thermal sensitivity to cold across the human body. Additionally, while exercise is known to cause a cold stimulus to be perceived as less unpleasant according to the principle of thermal alliesthesia, less has been reported on the effects of exercise on thermal sensitivity to cold. With applications mainly related to clothing insulation and design in mind, the present research project aimed to investigate thermal sensitivity to cold at whole body segments, as well as within body segments, at rest and during exercise. Additionally, a comparison of thermal sensitivity to cold between genders and between ethnic groups was also performed

Upper and lower body sensitivity to cold at rest and during exercise

Upper and lower body sensitivity to cold at rest and during exercis

Female thermal sensitivity to hot and cold during rest and exercise

Regional differences in thermal sensation to a hot or cold stimulus are often limited to male participants, in a rested state and cover minimal locations. Therefore, magnitude sensation to both a hot and cold stimulus were investigated during rest and exercise in 8 females (age: 20.4±1.4years, mass: 61.7±4.0kg, height: 166.9±5.4cm, VO2max: 36.8±4.5ml·kg-1·min-1). Using a repeated measures cross over design, participants rested in a stable environment (22.3±0.9°C, 37.7±5.5% RH) whilst a thermal probe (25cm2), set at either 40°C or 20°C, was applied in a balanced order to 29 locations across the body. Participants reported their thermal sensation after 10s of application. Following this, participants cycled at 50% VO2max for 20min and then 30% VO2max whilst the sensitivity test was repeated. Females experienced significantly stronger magnitude sensations to the cold than the hot stimulus (5.5±1.7 and 4.3±1.3, p<0.05, respectively). A significant effect of location was found during the cold stimulation (p<0.05). Thermal sensation was greatest at the head then the torso and declined towards the extremities. No significant effect of location was found in response to the hot stimulation and the pattern across the body was more homogenous. In comparison to rest, exercise caused a significant overall reduction in thermal sensation (5.2±1.5 and 4.6±1.7, respectively, p<0.05). Body maps were produced for both stimuli during rest and exercise, which highlight sensitive areas across the body

A database of static clothing thermal insulation and vapor permeability values of non-western ensembles for use in ASHRAE Standard 55, ISO 7730, and ISO 9920 CH-15-018 (RP-1504)

Four different thermal manikins (male and female shapes) in three different laboratories (UK, Sweden, and China) were used to determine the clothing thermal insulation values of 52 non-Western, mainly indoor clothing ensembles in order to expand the existing clothing database for use with ANSI/ ASHRAE Standard 55-2013, Thermal Environmental Conditions for Human Occupancy (ASHRAE 2013a), ISO Standard 7730-2005, Ergonomics oftheThermal Environment—Analytical Determination and Interpretation of Thermal Comfort Using Calculation of the PMV and PPD Indices and Local Thermal Comfort Criteria (ISO 2005), and ISO Standard 9920-2009,Ergonomics of the Thermal Environment—Estimation of Thermal Insulation and Water Vapour Resistance of a Clothing Ensemble (ISO 2009). Insulation values varied over manikins, which is attributed to their different shapes and the different fit of the clothing. The mean value over three manikins is reported (with standard deviation) to include this potential real-life variation in the results. The relation of the clothing surface area factor to intrinsic clothing insulation was found to be different from that published for Western clothing. Prediction equations for the clothing surface area factor fcl based on the new data had only limited predictive power, which, however, was also the case for those obtained in the past for Western clothing. This issue seems to be commonly overlooked, as the use of these prediction equations is widespread. It has to be concluded that reliable fcl values can only be obtained when they are actually measured, as in the present work. However, we suggest that the concept of the fcl factor for the non-Western clothing may not be appropriate and may require further attention in research, as wide-falling-robes and gowns do not match the cylindrical clothing and air layer model on which the fcl concept is based. In summary, the results provide an extensive database of insulation values of non-Western clothing that is expected to be a valuable addition to ASHRAE Standard 55-2013 (ASHRAE 2013a), ISO Standard 7730-2005 (ISO 2005), and ISO Standard 9920-2009 (ISO 2009)

Report on manikin measurements for ASHRAE 1504-TRP: Extension of the Clothing Insulation Database for Standard 55 and ISO 7730 to provide data for Non-Western Clothing Ensembles, including data on the effect of posture and air movement on that insulation. Results of Cooperative Research between the American Society of Heating Refrigerating and Air Conditioning Engineers, Inc., and the Universities of Loughborough, Lund, Cornell and Hong Kong.

ASHRAE standard 55, ISO 7730 and chapter 9 in ASHRAE Handbook-Fundamentals titled ‘thermal comfort’ provide guidance for the assessment of thermal comfort in buildings. As inputs, the method uses climate parameters, the users’ activity level and the clothing insulation of the garments worn by the occupants. The standard provides guidance on the determination of these parameters and provides examples of values for activity level and clothing insulation. However, for the latter, the emphasis is on western style clothing, while in large parts of the world other clothing styles are worn, e.g. shalwar kameez in Pakistan, African clothing in Nigeria or Sarees in India. In order to use the methodology of ASHRAE 55 in non-western regions, insulation data for such clothing is required. In the present project, ASHRAE 1504-RP, such data was collected for a range of non-western clothing types. Four different thermal manikins (male and female shapes) in three different laboratories (UK, Sweden and China), were used to determine the clothing insulation values of 52 clothing configurations. These fifty two configurations were also tested for the effects of air velocity on insulation and forty three were tested for the effects of posture (sitting) and walking. The observed reductions in insulation for both air velocity and walking are higher than those presented in the literature for western ensembles, emphasizing the need for these new data. This effect is most likely related to more open weave fabrics and loose fit designs. Similarly the relation of the clothing surface area factor to intrinsic clothing insulation was different from that published for western clothing. Prediction equations for the clothing surface area factor fcl, based on the new data only had limited predictive power, which however was also the case for those obtained in the past for western clothing. This issue seems to be commonly overlooked, as the use of these prediction equations is widespread. It has to be concluded that reliable fcl values can only be obtained when these are actually measured as in the present work. Having said this, the concept of the fcl factor for the non-western clothing may not work in the first place, as the wide falling robes and gowns do not match the cylindrical clothing and air layer model on which the fcl concept is based. The results provide an extensive database of insulation values of non-western clothing styles in different wear configurations, in different air velocities, postures and movement. As such this is expected to be a valuable addition to ASHRAE 55 and ISO 7730 and ISO 9920. In addition, data obtained on the insulation of individual body parts can be used by CFD modelers to incorporate realistic insulation data in their models

Assessing the lower temperature limit for comfort in footwear

When selecting clothing and equipment for use in the cold, consumers often receive only limited guidance from product information provided by manufacturers. In the area of sleeping bags the introduction of standards for their climatic range assessment, though often heavily debated by manufacturers, has undoubtedly provided consumers with guidance. Currently no such standards exist for outdoor footwear. Many manufacturers of footwear do claim certain lower temperature limits, going to -40ºC in some cases. No information is however provided on how this is tested and what criteria are applied. Kuklane et al. (1999) did several studies on the relation between footwear insulation and comfort range, but so far this has to our knowledge not led to the development of a standard. In the present study, following up on work by Kuklane, an attempt was made to collect physiological data that may be used in setting criteria for the lower temperature range of footwear