Heat Stress in Individuals With Schizophrenia

University of Ottawa

Status: Enrolling

Conditions: Cognitive Change; Physiological Stress; Heat Stress

Treatments: Other: Simulated exposure to indoor overheating

Study type: Interventional

Funder types: Other

Identifiers

NCT07383324

HEPRU-2026-01-A

Details and patient eligibility

About

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.

Enrollment: 10 estimated patients

Sex: All

Ages: 18 to 85 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

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

Exclusion criteria

• 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.

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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10 participants in 2 patient groups

Exposure to indoor temperature upper limit of 26°C

Experimental group

Description:

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

Treatment:

Other: Simulated exposure to indoor overheating

Exposure to hot indoor environment of 36°C

Experimental group

Description:

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

Treatment:

Other: Simulated exposure to indoor overheating