Exploring the human thermoneutral zone - A dynamic approach.

To date, the position and shape of the human thermoneutral zone (TNZ) remain uncertain. Indications exist that the individual TNZ might be influenced by age, body composition and level of acclimatisation. The objective of the present study was to explore the individual metabolic TNZ, using dynamic thermal conditions to assess both metabolic lower and upper critical temperatures (LCT and UCT) and, secondly, to test the effect of passive mild heat acclimation on the human metabolic TNZ.

Correlated colour temperature of morning light influences alertness and body temperature.

Though several studies have reported human alertness to be affected by the intensity and spectral composition of ambient light, the mechanism behind this effect is still largely unclear, especially for daytime exposure. Alerting effects of nocturnal light exposure are correlated with melatonin suppression, but melatonin levels are generally low during the day. The aim of this study was to explore the alerting effect of light in the morning for different correlated colour temperature (CCT) values, as well as its interaction with ambient temperature.

Improving rational thermal comfort prediction by using subpopulation characteristics: A case study at Hermitage Amsterdam.

This study aims to improve the prediction accuracy of the rational standard thermal comfort model, known as the Predicted Mean Vote (PMV) model, by (1) calibrating one of its input variables "metabolic rate," and (2) extending it by explicitly incorporating the variable running mean outdoor temperature (RMOT) that relates to adaptive thermal comfort. The analysis was performed with survey data ( = 1121) and climate measurements of the indoor and outdoor environment from a one year-long case study undertaken at Hermitage Amsterdam museum in the Netherlands. The PMVs were calculated for 35 survey days using (1) an assumed metabolic rate, (2) a calibrated metabolic rate found by fitting the PMVs to the thermal sensation votes (TSVs) of each respondent using an optimization routine, and (3) extending the PMV model by including the RMOT.

Thermophysiological adaptations to passive mild heat acclimation.

Passive heat acclimation (PMHA) reflects realistic temperature challenges encountered in everyday life. Active heat acclimation, combining heat exposure and exercise, influences several important thermophysiological parameters; for example, it decreases core temperature and enhances heat exchange via the skin. However, it is unclear whether PMHA elicits comparable adaptations.

The impact of morning light intensity and environmental temperature on body temperatures and alertness.

Indoor temperature and light exposure are known to affect body temperature, productivity and alertness of building occupants. However, not much is known about the interaction between light and temperature exposure and the relationship between morning light induced alertness and its effect on body temperature. Light intensity and room temperature during morning office hours were investigated under strictly controlled conditions.