A Preliminary Study Assessing the Effectiveness of a 26 °C Indoor Temperature Limit on Physiological Responses in Children
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 10
- 试验地点
- 1
- 主要终点
- Core temperature (Peak) during daylong exposure to indoor overheating
研究概览
简要总结
Communities worldwide are experiencing increasing heat extremes that challenge the limits of human thermoregulation, particularly among vulnerable populations such as children. Compared with adults, children are more susceptible to heat related illness due to less efficient thermoregulatory systems and difficulty recognizing early signs of heat stress. In addition, prolonged heat exposure can adversely affect their mental health, contributing to cognitive decline, heightened anxiety, and irritability. As children spend substantial time in hot environments at school and at home, and as these conditions intensify with climate change, actions to safeguard their health are essential. Yet our understanding of heat exposure effects in children remains incomplete, hindering the development of evidence based strategies to protect them.
To address this gap, the investigators aim to evaluate whether an indoor temperature limit of 26 °C (45 percent relative humidity), the upper threshold recommended to protect older adults, can effectively prevent dangerous increases in physiological strain and declines in cognitive function in children during a simulated daylong heatwave. The preliminary study will assess physiological and cognitive responses in children aged 10 to 15 years during a 6 hour exposure (approximating a typical school day) to two conditions: (1) the recommended indoor temperature upper limit (26 °C) and (2) a high heat condition representative of homes and schools without air conditioning during extreme heat events (36 °C). In both conditions, children will remain seated at rest while wearing light clothing (t shirt and shorts), with the exception of performing 15 minutes of stepping exercise (6-6.5 METS) each hour (excluding the lunch period) to reflect typical daily activity in a school setting. This experimental design will allow investigators to determine whether maintaining indoor temperatures at the recommended upper limit for older adults sufficiently mitigates physiological strain in children.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Single (Outcomes Assessor)
入排标准
- 年龄范围
- 10 Years 至 15 Years（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •English or French speaking.
- •Ability to provide informed assent.
排除标准
- •Chronic health conditions
- •Endurance exercise training (greater than 3 sessions of vigorous exercise training per week for 30 minutes or more)
- •Restrictions to physical activity
研究组 & 干预措施
Exposure to hot indoor environment of 36°C
Participants exposed daylong (6 hours) to an indoor temperature maintained at 36°C and 45% relative humidity (humidex equivalent of 45).
干预措施: Simulated exposure to indoor overheating (Other)
Exposure to indoor temperature upper limit of 26°C
Participants exposed daylong (6 hours) to an indoor temperature maintained at 26°C and 45% relative humidity (humidex equivalent of 29).
干预措施: Simulated exposure to indoor overheating (Other)
结局指标
主要结局
Core temperature (Peak) during daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Peak rectal temperature (15 min average) during exposure. Rectal temperature is measured continuously throughout the 6 hour exposure to the simulated indoor overheating.
Core temperature (AUC) during daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Areas under the curve (AUC) of rectal temperature during the 6 hour exposure to the simulate indoor overheating.
Core temperature end of daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Rectal temperature measured at hour 6 of exposure to indoor overheating (15-min average).
Mean skin temperature (AUC) during daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Areas under the curve (AUC) of mean skin temperature as calculated over 7 body regions during the 6 hour exposure to the simulate indoor overheating.
Mean skin temperature end of daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Mean skin temperature measured over 7 body regions at hour 6 of exposure to indoor overheating (15-min average).
Heat rate (Peak) during daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Peak heart rate (15 min average) during exposure. Heart rate is measured continuously throughout the 6 hour exposure to the simulated indoor overheating.
Mean skin temperature (Peak) during daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Peak mean skin temperature (15 min average) during exposure. Mean skin temperature as calculated from skin temperature measured across 7 body regions is measured continuously throughout the 6 hour exposure to the simulated indoor overheating.
Heart rate (AUC) during daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Areas under the curve (AUC) of heart rate during the 6 hour exposure to the simulate indoor overheating.
Heart rate end of daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Heart rate measured at hour 6 of exposure to indoor overheating (15-min average).
Systolic blood pressure during daylong exposure to indoor overheating
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Systolic blood pressure measured in triplicate via automated oscillometry (\~60 seconds between measures).
Diastolic blood pressure during daylong exposure to indoor overheating.
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Diastolic blood pressure measured in triplicate via automated oscillometry (\~60 seconds between measures).
Reaction time during daylong exposure to indoor overheating (cognitive function).
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of reaction time. Participants will be asked to initiate a movement of the device in response to a visual cue.
Hydration status during daylong exposure to indoor overheating
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Hydration status measured via assessing the urine specific gravity of a urine sample.
Impulse control during daylong exposure to indoor overheating (cognitive function).
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of impulse control. Participants will be asked to respond to both "go" and "no-go" visual cues. In response to the "go" cue, participants will initiate a movement of the device.
BTrackS Balance Assessment during daylong exposure to indoor overheating (postural stability).
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
To assess postural stability, participants will be asked to stand on a BTracks force plate with their feet spread out to shoulder width, hand on their hips and eyes closed. The assessment will comprise of four trials (one practice trial) lasting 20 seconds in length and 20 seconds between trials. Center of pressure (COP) vector data along vertical (y) and horizontal (x) axes will be summed for the total path excursion length (cm) during each trial
Thermal sensation scale during daylong exposure to indoor overheating
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Thermal sensation assessed via a visual analog scale (How hot do you feel?) ranging from "extremely hot" to "neutral".
Memory recall during daylong exposure to indoor overheating (cognitive function).
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of memory recall. Participants complete both a delayed recall test and a working memory test.
Fluid loss during daylong exposure to indoor overheating
时间窗: At end of 6 hour daylong exposure
Fluid loss calculated as the change in body mass during each exposure presented as a percentage of baseline body mass (corrected for food consumption).
CDC 4-Stage Balance Test during daylong exposure to indoor overheating (postural stability).
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
To assess postural stability, participants hold a tablet to their chest, then auditory cues guide participants through four consecutive stances, feet side by side, instep of one foot touching the big toe of the other foot, tandem stand with one foot in front of the other, heel touching toe, and stand on one foot. The balance assessment will be evaluated based on movement detected by an accelerometer integrated into the hardware of the tablet device (Sway Medical Inc).
Executive function during daylong exposure to indoor overheating (cognitive function).
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of executive function. Participants will complete the Cued Stroop test, in which they are presented a sequence of congruent, neutral and incongruent color-word tasks.
Thermal sensation 2 scale during daylong exposure to indoor overheating
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Thermal sensation assessed via a visual analog scale ("How do you feel?") ranging from "hot" to "cold"(midpoint: neutral)
Thermal comfort scale during daylong exposure to indoor overheating
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Thermal comfort assessed via a visual analog scale ("How comfortable does your body temperature feel?") ranging from "very uncomfortable" to "comfortable".
Fluid consumption during daylong exposure to indoor overheating
时间窗: At end of 6 hour daylong exposure
Average hourly fluid consumption calculated by weighing participant water intake at the start and end of each hour of exposure (normalized to the exposure duration).
Thirst sensation scale during daylong exposure to indoor overheating
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Thirst sensation assessed via a visual analog scale ranging from very, very thirsty to not thirsty at all.
Feel good scale during daylong exposure to indoor overheating
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Feel good scale assessed via a visual analog scale (How good do you feel?) ranging from "very good" to "very bad" (midpoint: neutral)
Activity levels during daylong exposure to indoor overheating
时间窗: End of 6 hour daylong exposure
Activity levels assessed via a wearable monitor (Actical) containing an accelerometer worn on the wrist and hip.
Perceived exertion scale during daylong exposure to indoor temperature limit.
时间窗: At the start (hour 0) and end of 6 hour daylong exposure
Perceived exertional assessed via a visual analog scale ("How hard are you working?") ranging from "no exertional at all" to "maximal exertion"
次要结局
- Profiles of Mood States (POMS) during daylong exposure to indoor overheating(At the start (hour 0) and end of 6 hour daylong exposure)
- Environmental Symptoms Questionnaire (ESQ) during daylong exposure to indoor overheating(At the start (hour 0) and end of 6 hour daylong exposure)
研究者
Glen P. Kenny
Full Professor, University Research Chair
University of Ottawa