Indoor Overheating and Physiological Strain in Older Adults With COPD

NCT07852910 | Not Yet Recruiting

• 1 other identifier: H-08-26-13258
• Study Type: interventional
• Target: 18
• Locations: 1 country
• Sites: 1

Brief Summary

During warm weather, homes without air conditioning can stay hot for long periods, and most heat-related health problems in Canada happen indoors rather than outdoors. Health Canada recommends that indoor temperatures not exceed 26 °C in homes occupied by people who are more susceptible to heat. That recommendation is based largely on population-level evidence, and very little is known about how susceptible individuals actually respond, physiologically, when indoor temperatures rise above it. Older adults living with chronic obstructive pulmonary disease (COPD) are among the groups identified as more susceptible to heat. COPD involves persistent airflow limitation, reduced lung and cardiovascular reserve, and altered cellular stress responses. Despite this, no laboratory study has directly measured how adults with COPD respond to a full day spent indoors in warm conditions. This randomized crossover trial will measure how older adults with COPD respond to two different indoor environments, each experienced for eight hours on separate days at least one week apart. One day is spent at the recommended indoor temperature limit and the other at a warmer temperature representative of conditions recorded inside Canadian homes during hot weather. Participants remain seated and rest throughout; no exercise or work is performed. Throughout each day, the research team continuously measures core body temperature, skin temperature, heart rate, and measures blood pressure, lung function, breathlessness, thermal comfort, cognitive performance, and balance at set time points. Blood and urine samples are collected at the start and end of each day. Participants are monitored continuously by trained staff. The results are intended to strengthen the evidence base behind Canadian indoor temperature guidance and to inform recommendations for protecting people living with chronic lung disease during hot weather.

Conditions

Chronic Obstructive Pulmonary Disease (COPD); Heat Stress

Keywords

indoor overheating; extreme heat; thermoregulation; core temperature; pulmonary function

Outcome Measures

Primary Outcomes (1)

• Core temperature (Peak)

  Peak rectal temperature (15 min average) during exposure. Rectal temperature is measured continuously throughout the simulated indoor overheating exposure.

  End of 8-hour exposure

Secondary Outcomes (29)

• Profiles of Mood States (POMS)

  At the start (hour 0) and end of exposure (hour 8)

• Environmental Symptoms Questionnaire (ESQ)

  At the start (hour 0) and end of exposure (hour 8)

• Orthostatic intolerance symptoms assessment

  At the start (hour 0) and end of exposure (hour 8)

• Arousal scale

  End of 8-hour exposure

• Thirst sensation scale

  End of 8-hour exposure

Study Arms (2)

Recommended indoor temperature limit (26 °C)

ACTIVE COMPARATOR

Eight-hour passive seated exposure to an indoor environment maintained at 26 °C and 45% relative humidity, corresponding to the recommended upper indoor temperature limit for heat-susceptible occupants.

Other: Simulated indoor thermal environment

Indoor overheating (36 °C)

EXPERIMENTAL

Eight-hour passive seated exposure to an indoor environment maintained at 36 °C and 45% relative humidity, representing warm indoor conditions recorded inside Canadian dwellings without mechanical cooling during heat events.

Other: Simulated indoor thermal environment

Interventions

Simulated indoor thermal environment OTHER

Day-long (8 h) passive exposure in a climate-controlled environmental chamber at a set air temperature and relative humidity. Participants remain seated or resting.

Indoor overheating (36 °C); Recommended indoor temperature limit (26 °C)

Eligibility Criteria

• Age: 60 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged 60 to 80 years
• Physician diagnosis of chronic obstructive pulmonary disease made at least 5 years previously
• Clinically stable, with no acute exacerbation or active respiratory infection in the preceding 6 weeks
• Current non-smoker
• Able to communicate in English or French and to provide written informed consent

You may not qualify if:

• Physical restriction preventing safe participation, including unstable cardiac or pulmonary disease, uncontrolled hypertension (resting blood pressure exceeding 150/95 mmHg), severe arthritis, renal impairment, active proliferative retinopathy, history of disabling stroke, or intermittent claudication
• Recent change in medications judged by the investigators to make participation inadvisable
• Cardiac abnormalities identified on electrocardiogram during the screening exercise test
• Regular work or exercise in hot environments (heat acclimatized)

Sponsors & Collaborators

• University of Ottawa: lead

Study Sites (1)

University of Ottawa

Ottawa, Ontario, K1N 6N5, Canada

Location

MeSH Terms

Conditions

Pulmonary Disease, Chronic Obstructive; Heat Stress Disorders

Condition Hierarchy (Ancestors)

Lung Diseases, Obstructive; Lung Diseases; Respiratory Tract Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Wounds and Injuries

Study Officials

• Glen P Kenny, PhD

  University of Ottawa

  STUDY DIRECTOR

Central Study Contacts

Nicholas Goulet, MSc

CONTACT

613-322-9930; ngoul043@uottawa.ca

Pascal Imbeault, PhD

CONTACT

imbeault@uottawa.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 25, 2026
• First Posted: October 1, 2026
• Study Start (Estimated): October 13, 2026
• Primary Completion (Estimated): May 31, 2027
• Study Completion (Estimated): May 31, 2027
• Last Updated: October 1, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)