Heat Stress in Individuals With Schizophrenia

NCT07383324 | Recruiting

• 1 other identifier: HEPRU-2026-01-A
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

Schizophrenia is a severe mental illness affecting approximately 24 million people worldwide and is associated with more than double the all cause mortality risk of the general population. Emerging evidence demonstrates that elevated temperatures acutely worsen mental health symptoms and significantly increase the risk of heat related morbidity and mortality. For people living with schizophrenia, prolonged exposure to heat can exacerbate psychiatric symptoms, impair judgment and decision making, and reduce the ability to engage in protective behaviors such as increasing hydration, reducing clothing, improving ventilation, or seeking cooler environments. As a result, individuals with schizophrenia may experience higher rates of heat related illness. To date our understanding of heat exposure effects in individuals with schizophrenia remains incomplete, hindering the development of evidence-based strategies to protect them. Thus, the primary objective of this exploratory study is to gather preliminary data on the effects of indoor overheating on physiological responses (core body temperature and cardiovascular function), cognitive performance (attention, working memory, and reaction time), and mood in adults with schizophrenia. Specifically, we will assess whether maintaining indoor conditions at the upper recommended temperature limit for older adults (26°C, 45% relative humidity \[RH\]; PMID: 38329752) is sufficient to mitigate physiological strain compared with exposure to a hot indoor environment (36°C, 45% RH) representative of non-air-conditioned homes during extreme heat events in individuals with schizophrenia. In both conditions, the individual will remain seated at rest while wearing light clothing (t shirt and shorts), with the exception of performing 15 minutes of stepping exercise (4-4.5 METS) each hour (excluding the lunch period) to reflect typical daily activities of daily living.

Conditions

Physiological Stress; Heat Stress; Cognitive Change

Keywords

Indoor overheating; Indoor temperatures; Heat wave; Thermoregulation; Schizophrenia; Heat strain; Heat vulnerability; Hyperthermia; Mental health; Thermal comfort; Physical activity

Outcome Measures

Primary Outcomes (1)

• Core temperature (Peak) during daylong exposure to indoor overheating

  Peak core (indexed by visceral temperature) temperature (15 min average) during exposure. Visceral temperature is measured continuously throughout the 6 hour exposure to the simulated indoor overheating.

  End of 6 hour daylong exposure

Secondary Outcomes (28)

• 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

• Perceived exertion scale during daylong exposure to indoor temperature limit.

  At the start (hour 0) and end of 6 hour daylong exposure

• Activity levels (total steps taken) during daylong exposure to indoor overheating

  End of 6 hour daylong exposure

• Feel good scale during daylong exposure to indoor overheating

  At the start (hour 0) and end of 6 hour daylong exposure

Study Arms (2)

Exposure to indoor temperature upper limit of 26°C

EXPERIMENTAL

Participants exposed daylong (6 hours) to an indoor temperature maintained at 26°C and 45% relative humidity (humidex equivalent of 29).

Other: Simulated exposure to indoor overheating

Exposure to hot indoor environment of 36°C

EXPERIMENTAL

Participants exposed daylong (6 hours) to an indoor temperature maintained at 36°C and 45% relative humidity (humidex equivalent of 45).

Other: Simulated exposure to indoor overheating

Interventions

Simulated exposure to indoor overheating OTHER

Individuals with schizophrenia exposed to a 6-hour simulated heat exposure

Exposure to hot indoor environment of 36°C; Exposure to indoor temperature upper limit of 26°C

Eligibility Criteria

• Age: 18 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• English or French speaking.
• Ability to provide informed consent.
• Individuals with and without schizophrenia or schizoaffective disorder.

You may not qualify if:

• Endurance exercise training (greater than 3 sessions of vigorous exercise training per week for 30 minutes or more)
• Restrictions to physical activity
• Any history of diagnoses for other psychiatric disorders deemed to make participation in the study inadvisable.

Sponsors & Collaborators

• University of Ottawa: lead

Study Sites (1)

University of Ottawa

Ottawa, Ontario, K1N 6N5, Canada

RECRUITING

MeSH Terms

Conditions

Heat Stress Disorders; Schizophrenia; Hyperthermia; Psychological Well-Being; Motor Activity

Condition Hierarchy (Ancestors)

Wounds and Injuries; Schizophrenia Spectrum and Other Psychotic Disorders; Mental Disorders; Body Temperature Changes; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Personal Satisfaction; Behavior

Study Officials

• Glen P Kenny, PhD

  University of Ottawa

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Glen P Kenny, PhD

CONTACT

613-562-5800; gkenny@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: PRINCIPAL INVESTIGATOR
• PI Title: Full Professor, University Research Chair

Study Record Dates

• First Submitted: January 20, 2026
• First Posted: February 3, 2026
• Study Start: November 8, 2025
• Primary Completion (Estimated): May 31, 2027
• Study Completion (Estimated): July 1, 2027
• Last Updated: April 23, 2026

Record last verified: 2026-04

Locations

CA (1)