Identifying the Limits of Survivability in Heat-exposed Older Females

Launched by UNIVERSITY OF OTTAWA · Jun 14, 2025

Keywords

ClinConnect Summary

This clinical trial is studying how older women’s bodies handle extreme heat, especially when the heat becomes too much for their bodies to cool down properly. Because of climate change, heat waves are becoming more common, and older women may be at higher risk for heat-related health problems. This study aims to find the exact point where the body can no longer manage the heat, which is important for understanding when heat becomes dangerous. Researchers will test how the body’s temperature and heart respond to increasing heat and humidity, as well as how heat affects thinking and mood.

Women who are 65 years or older, non-smokers, and able to understand English or French may be eligible. The study includes women with or without certain common health conditions like controlled high blood pressure or well-managed type 2 diabetes. Participants will take part in five sessions where they will spend time in a warm environment with controlled heat and humidity levels. Their body temperature will be closely monitored to find the point where heat becomes too much to handle safely. This helps researchers understand how to better protect older women during extreme heat events. Participants should be in generally stable health without serious heart problems or other conditions that could make the study unsafe.

Gender

FEMALE

Eligibility criteria

• Inclusion Criteria:
• • Non-smoking.
• • English or French speaking.
• • Ability to provide informed consent.
• • With or without a) chronic hypertension (elevated resting blood pressure; as defined by Heart and Stroke Canada and Hypertension Canada), b) type 2 diabetes as defined by Diabetes Canada, with at least 5 years having elapsed since time of diagnosis
• Exclusion Criteria:
• • Episode(s) of severe hypoglycemia (requiring the assistance of another person) within the previous year, or inability to sense hypoglycemia (hypoglycemia unawareness).
• • Serious complications related to diabetes (gastroparesis, renal disease, uncontrolled hypertension, severe autonomic neuropathy).
• • Uncontrolled hypertension - BP \>150 mmHg systolic or \>95 mmHg diastolic in a sitting position.
• • Restrictions in physical activity due to disease (e.g. intermittent claudication, renal impairment, active proliferative retinopathy, unstable cardiac or pulmonary disease, disabling stroke, severe arthritis, etc.).
• • Use of or changes in medication judged by the patient or investigators to make participation in this study inadvisable.
• • Cardiac abnormalities identified during screening