Thermal Comfort in School Classes in the Era of Global Warming: A Prospective Multicenter Study.

BACKGROUND: We investigated adolescents' feelings of thermal comfort during the educational process in various geographical locations far apart and present recommendations for the adjustment of the thermal environment in schools. METHODS: The prospective international multicenter study took place in 8 locations on different continents. The survey in the form of a questionnaire was carried out among 2800 healthy high school students. The study was divided into "cold season survey," "warm-season survey," and heat wave survey. RESULTS: The statistically significant difference between the "cold season survey" score of 4.04 (discomfort) and "warm-season survey" score of 3.47 (slight discomfort) (p = .04) indicates that students feel more thermal discomfort during winter months in all 8 locations. The heat wave survey score was 4.53 (discomfort). During the cold season, 29.24% of high school students felt themselves in full thermal comfort and 76.48% of the students felt themselves relatively comfortable (slightly cool-comfortable-slightly warm). CONCLUSIONS: Even during the ongoing process of climate change, the cold season discomfort remains the main problem for students in classes. This tendency is present in different continents as a universal problem. We recommend keeping an entrance hall and classroom temperatures at different levels and to advise students about proper clothing.

The range of normative surface skin temperature changes in adolescents: prospective multicenter study.

AIM: We aimed to establish a normative range of surface skin temperature (SST) changes due to blood redistribution in adolescents and to register the time needed for complete postural change-related blood redistribution. METHODS: The healthy volunteers (age 15-18, n = 500, M 217, F 283) were recruited for this prospective multicenter study. The volunteers were asked to keep one extremity down and another extremity up in supine rest, sitting with straight legs, and upright rest. We obtained temperature readings being taken from the tips of the middle fingers and temperature readings from the tips of the first toes at the ambient temperature of 25 °C and 30 °C. The control group consisted of a 100 of adult volunteers. RESULTS: The resting temperature of the middle fingers for a sitting participant was 28.6 ± 0.8 °C. The physiological change of this temperature during body position changes was 4.5 ± 1.1 °C and for most of the participants remained within the 26.5-31.5 °C range at 25 °C. For the toe, physiological skin temperature range was 25.5-33 °C. At 30 °C, these ranges were 27-33 °C for the fingers and 27-34 °C for the toes. On average, 2-3 min were needed for such temperature changes. CONCLUSION: At normal room temperature, the SST of thermoneutral adolescents may vary within a range of approximately 5 °C only due to the blood redistribution in the body. This range is specific for each person due to individual peculiarities of the vasomotor activity. This normative range of SSTs should be taken into account during investigations of thermoregulation.

Normative surface skin temperature changes due to blood redistribution: A prospective study.

The continuing development and manufacture of infrared devices, together with improvements in thermal body mapping techniques have simplified surface skin thermography which is being used more extensively than ever before. Normative thermography data, however, remains incomplete. A normative blood redistribution range of skin temperatures was established for use as a reference for laboratory infrared thermography (IT), thermal body mapping, and mass fever screenings. 500 healthy volunteers participated in this prospective study. To determine the maximum range of the skin temperature changes due to the posture-related physiological blood redistribution, the volunteers were asked to keep one extremity up and another extremity down whilst lying, sitting, and standing. We obtained 6000 hand and 400 foot temperature readings. The normal temperature was 29.1 ±â€¯0.6 °C for the middle fingers and 27.8 ±â€¯0.7 °C for the toes. The physiological temperature change during body position changes ranged from 4 to 6 °C (fingers: 27-31 °C; toes: 26-32 °C). At normal room temperature, the surface skin temperature may vary within this range due to blood redistribution. These changes reflect the individual variability of vasomotor activity. This physiological range of temperatures should be taken into account during IT and other thermography-involved investigations.