Impact of Indoor Overheating on Physiological Strain in Children

NCT ID: NCT07261202

Last Updated: 2025-12-11

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-11-08
• Study Completion Date: 2026-12-31

Brief Summary

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.

Conditions

Heat Stress; Physiological Stress; Cognitive Change

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: SINGLE

Study Groups

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).

Group Type: EXPERIMENTAL

Simulated exposure to indoor overheating

Intervention Type: OTHER

Children exposed to a 6-hour simulated heat exposure

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).

Group Type: EXPERIMENTAL

Simulated exposure to indoor overheating

Intervention Type: OTHER

Children exposed to a 6-hour simulated heat exposure

Interventions

Simulated exposure to indoor overheating

Children exposed to a 6-hour simulated heat exposure

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• English or French speaking.
• Ability to provide informed assent.

Exclusion Criteria

• 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

• Minimum Eligible Age: 10 Years
• Maximum Eligible Age: 15 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Ottawa

OTHER

Sponsor Role: lead

Responsible Party

Glen P. Kenny

Full Professor, University Research Chair

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Glen P Kenny, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Ottawa

Locations

University of Ottawa

Ottawa, Ontario, Canada

Site Status: RECRUITING

Countries

Canada

Central Contacts

Glen P Kenny, PhD

Role: CONTACT

gkenny@uottawa.ca

613-562-5800 ext. 4282

Facility Contacts

Glen P Kenny, PhD

Role: primary

gkenny@uottawa.ca

613-562-5800 ext. 4282

Other Identifiers

HEPRU-2025-10-A

Identifier Type: -

Identifier Source: org_study_id