Effects of Color Temperature of Fluorescent Lamps on Body Temperature Regulation in a Moderately Cold Environment.

Abstract

A study on the effects of different color temperatures of fluorescent lamps on skin and rectal temperatures in a moderately cold environment involving (i) changes in skin temperature of 7 male subjects exposed to an ambient temperature ranging from 28°C to 18°C (experiment I) and (ii) changes in skin and rectal temperatures and metabolic heat production of 11 male subjects exposed to ambient temperature of 15°C for 90 min (Experiment II) was conducted. In Experiment I, the reduction of mean skin temperature from the control value was significantly greater under 3000 K than under 5000 K or 7500 K lighting. In Experiment II, the reductions in mean skin temperature and rectal temperature were respectively greater and smaller under 3000 K than those under 5000 K or 7500 K lighting. However, metabolic heat production was not affected by color temperature conditions. The relationships between morphological and physiological parameters revealed that no significant relation of rectal temperature to body surface area per unit body weight was found only under 3000 K. Furthermore, while the mean skin temperature was independent on the mean skinfold thickness under 3000 K, a significant negative correlation between the rectal and mean skin temperatures was observed. Therefore, body heat loss might be suppressed effectively by increasing the vasoconstrictor tone under a color temperature of 3000 K, and the body shell was dependent only on morphological factors under 5000 K and 7500 K lighting.

Short‐wavelength enrichment of polychromatic light enhances human melatonin suppression potency

“…Lamps with higher CCT were found to evoke a stronger melatonin suppression compared to lamps with lower CCT in healthy humans [49][50][51]. Additionally, compared to low CCT light, higher CCT light was observed to have a more potent effect on reducing the nocturnal fall of core temperature, decreasing body temperature change to cold challenge, and increasing the morning rise in core temperature [50,52,53]. Furthermore, EEG frequency has been shown to increase under high CCT as compared to lower CCT illumination [54].…”

Photoreception for Circadian, Neuroendocrine, and Neurobehavioral Regulation

“…Specifically, it was found that lights with a higher color temperature evoke stronger melatonin suppression compared to lamps with a lower color temperature in healthy humans (Morita and Tokura, 1998;Sato et al, 2005). Additionally, higher color temperature fluorescent lamps have a more potent effect on core body temperature than low color temperature lamps (Morita and Tokura, 1998;Yasukouchi et al, 2000). Further, blood pressure and EEG frequency have been shown to increase under a high color temperature as compared to lower color temperatures (Noguchi and Sakaguchi, 1999;Yasukouchi and Ishibashi, 2005).…”

Variations in the Light-induced Suppression of Nocturnal Melatonin with Special Reference to Variations in the Pupillary Light Reflex in Humans

“…Neural regions affecting the central nervous system (CNS), autonomic nervous system (ANS), motor, hormone and immune systems are extensively distributed along the transmission pathway; thus lighting may affect an extensive range of physiological functions as possible non-visual effects (Yasukouchi and Ejima, 1998;Yasukouchi et al, 2000;Berson, 2003;CIE, 2004). This implies that individual differences in MS are also related to individual differences in physiological functions, mentioned here in responses to the same light stimulus.…”