Evidence map›Paper›PMID 41188435›Full record

ArticleScientific reports2025

Acute effect of light and time of day on thermal physiology, perception, and behavior.

Abdelkader Elkounni, Marika Vellei, Jérôme Le Dréau, Marcel Schweiker, Christian Inard

Abstract read
In one paragraph

Article in Scientific reports, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Abdelkader ElkounniLaboratory of Engineering Sciences for the Environment LaSIE UMR CNRS 7356, La Rochelle University, 17000 La Rochelle, France. abdelkader.elkounni@univ-lr.fr.
Marika VelleiUniversity of Bordeaux, CNRS, Bordeaux INP, I2M,UMR 5295, F-33400, Talence, France.
Jérôme Le DréauLaboratory of Engineering Sciences for the Environment LaSIE UMR CNRS 7356, La Rochelle University, 17000 La Rochelle, France.
Marcel SchweikerHealthy Living Spaces Lab, Medical Faculty, Institute for Occupational, Social and Environmental Medicine, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany.
Christian InardLaboratory of Engineering Sciences for the Environment LaSIE UMR CNRS 7356, La Rochelle University, 17000 La Rochelle, France.

Funding

HORIZON EUROPE Marie Sklodowska-Curie Actions 101073357
6 · The paper itself

Abstract

Implementing novel, human-centric building control strategies that account for the interaction of multidomain factors, light, temperature, and time of day, can enhance occupant comfort and promote energy savings. However, their successful implementations require a robust framework that clearly explains the physiological mechanisms through which light exposure influences thermal perception and evaluation. To date, most studies have primarily relied on the hue-heat hypothesis, which attributes changes in thermal assessment solely to visual color associations, overlooking the physiological impact of light, particularly blue-enriched bright light, on the circadian rhythm and thermoregulation. In this study, we investigated the influence of light intensity on thermal physiology, perception, and behavior within a circadian context, employing skin temperature measurements, subjective questionnaires, and fan-use behavior as outcome measures. 20 healthy adults participated in four experimental sessions combining two illuminance levels (bright vs. dim, with identical spectral composition) at two times of day (07:00 and 14:00) under warm conditions, both steady-state and fan-induced dynamic ones. Results showed that skin temperature followed its natural circadian rhythm, being lower in the early morning than at midday. Notably, bright light exposure significantly suppressed the circadian rise in skin temperature in the morning, shifted thermal sensation votes from slightly warm towards neutral, and improved thermal comfort votes compared to dim light or midday exposure. This effect was evident under steady-state warm conditions and persisted following fan use. In contrast, under the fan-induced slightly cool condition, neither light intensity nor time of day significantly affected thermal assessment. These findings underscore the fundamental role of circadian physiology in thermal comfort and suggest that strategically timed light and thermal exposure can optimize comfort by aligning ambient conditions with the body's internal rhythms.

Indexed as

BehaviorBody Temperature RegulationCircadian RhythmLightPerceptionAdultFemaleHumansMaleSkin TemperatureYoung Adult

Identifiers

PMID41188435
PMCPMC12586677

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.