Facial warming and tinted helmet visors

Abstract Tinted helmet visors have found applications in several areas as a means of reducing visual strain under bright conditions. For motorcyclists, new technologies which can rapidly change the level of tinting promise to make such visors more accessible, which is necessary to avoid safety risks. For these users, it is often important to minimize the heat load on the body. We studied the changes in the heat load on the face as a function of motorcycle helmet visor configuration (normal and tinted) using a thermal head manikin and ( n = 8 ) human subjects. Good agreement was found between the measured and perceived heat load, and this load was greatly reduced for moderate tinting levels. The optical transmission properties of the visor configurations largely explain the results. Our results suggest that visors optimized for infrared rejection would likely be perceived as an improvement. Relevance to industry The production of motorcycle and other tinted helmet visors could be aimed at multiple benefits, viz, visual and thermal protection and comfort. The role of comfort in the use of such products is important for industry, as well as knowledge of how to assess such effects.

[1]  Reader Dc,et al.  Head-temperature effects on physiology, comfort, and performance during hyperthermia. , 1982 .

[2]  J W Kaufman.  Estimated ventilation requirements for personal air-cooling systems. , 2001, Aviation, space, and environmental medicine.

[3]  Claes-Göran Granqvist,et al.  Electrochromic coatings and devices: survey of some recent advances , 2003 .

[4]  Phillip A. Bishop,et al.  Bicycle helmet ventilation and comfort angle dependence , 2004, European Journal of Applied Physiology.

[5]  René Rossi,et al.  Fire fighting and its influence on the body , 2003, Ergonomics.

[6]  N. Toy,et al.  Natural convection around the human head. , 1975, The Journal of physiology.

[7]  P. Payne,et al.  Bioengineering and the Skin , 1981, Springer Netherlands.

[8]  V. Candas,et al.  Thermoregulatory effects of three different types of head cooling in humans during a mild hyperthermia , 2000, European Journal of Applied Physiology.

[9]  J Gomes,et al.  The health of the workers in a rapidly developing country: effects of occupational exposure to noise and heat. , 2002, Occupational medicine.

[10]  P A Bishop,et al.  Simulated shuttle egress: role of helmet visor position during approach and landing. , 2001, Aviation, space, and environmental medicine.

[11]  E.J.G. Beeson,et al.  The CSI lamp as a source of radiation for solar simulation , 1978 .

[12]  P. A. Brühwiler,et al.  CO2 and O2 concentrations in integral motorcycle helmets. , 2005, Applied ergonomics.

[13]  J. A. Parrish,et al.  Optical radiation transfer in the human skin and applications in in vivo remittance spectroscopy , 1981 .

[14]  T. Ackland,et al.  Performance enhancement in rally car drivers via heat acclimation and race simulation. , 2001, Comparative biochemistry and physiology. Part A, Molecular & integrative physiology.

[15]  L. Berglund,et al.  Thermal sensation of the body as influenced by the thermal microclimate in a face mask. , 1987, Ergonomics.

[16]  Andris Azens,et al.  Electrochromic devices on polyester foil , 2003 .

[17]  Randi Eidsmo Reinertsen,et al.  Effects of wearing aircrew protective clothing on physiological and cognitive responses under various ambient conditions. , 2003, Ergonomics.

[18]  P. A. Brühwiler,et al.  Heated, perspiring manikin headform for the measurement of headgear ventilation characteristics , 2003 .

[19]  L A Temme,et al.  Visual acuity of the U.S. Navy jet pilot and the use of the helmet sun visor. , 1991, Aviation, space, and environmental medicine.

[20]  Peter Palffy-Muhoray,et al.  Technology for electronically varying helmet visor tint , 2000, Defense, Security, and Sensing.