Is a 26°C indoor temperature safe for older adults when wearing everyday clothes or doing normal activities?

Evaluation of the 26 °C Indoor Temperature Upper Limit Considering Clothing Insulation and Daily Activity in Older Adults

Not applicable Interventional University of Ottawa · NCT07189507

This trial will test whether keeping indoor temperatures at or below 26°C protects older adults from heat strain when they wear everyday clothing or do normal daily activities.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment10 (estimated)
Ages65 Years to 85 Years
SexAll
SponsorUniversity of Ottawa Academic / other
Locations1 site (Ottawa, Ontario)
Trial IDNCT07189507 on ClinicalTrials.gov

What this trial studies

Researchers will expose older adult participants to simulated indoor temperature conditions around the 26°C upper limit while varying clothing insulation and routine activity levels to mimic daily life. Participants will be monitored for physiological signs of heat strain such as heart rate, blood pressure, body temperature, and subjective heat perception. The study includes non-smoking English- or French-speaking adults with or without controlled hypertension or longstanding type 2 diabetes, excluding those with serious complications or uncontrolled blood pressure. Data will be used to determine whether the 26°C recommendation remains protective once clothing and activity-related internal heat production are considered.

Who should consider this trial

Good fit: Ideal candidates are older, non-smoking adults who speak English or French, can give informed consent, and may have controlled hypertension or type 2 diabetes diagnosed more than five years ago without serious complications.

Not a fit: People with uncontrolled hypertension, recent severe hypoglycemia, serious diabetes complications, or medical restrictions on physical activity are unlikely to benefit and are excluded.

Why it matters

Potential benefit: If successful, the results could refine public-health indoor temperature guidance to better protect older adults during heat events by accounting for clothing and activity.

How similar studies have performed: Previous research indicated a 26°C upper limit can be protective for heat-vulnerable older adults, but those studies did not account for clothing or activity-related heat burden, so this trial extends existing evidence by testing those factors.

Eligibility criteria

Show full inclusion / exclusion 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 your 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

Where this trial is running

Ottawa, Ontario

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Heat StressPhysiological StressIndoor overheatingIndoor temperaturesHeat waveThermoregulationHeat strainHeat vulnerability
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.