Cardiovascular Responses to Heat Waves in the Elderly
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ClinicalTrials.gov Identifier: NCT04538144 |
Recruitment Status :
Recruiting
First Posted : September 3, 2020
Last Update Posted : March 1, 2023
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Condition or disease | Intervention/treatment |
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Aging Hyperthermia | Other: Simulated heat wave |
Study Type : | Observational |
Estimated Enrollment : | 80 participants |
Observational Model: | Cohort |
Time Perspective: | Prospective |
Official Title: | Heat Waves in the Elderly: Reducing Thermal and Cardiovascular Consequences |
Actual Study Start Date : | January 19, 2021 |
Estimated Primary Completion Date : | August 31, 2026 |
Estimated Study Completion Date : | August 31, 2026 |
Group/Cohort | Intervention/treatment |
---|---|
Younger participants
Individuals aged 18-39 years
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Other: Simulated heat wave
Individuals will be exposed to thermoneutral climate conditions and two simulated heat wave conditions. |
Older participants
Individuals aged 65 years or older
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Other: Simulated heat wave
Individuals will be exposed to thermoneutral climate conditions and two simulated heat wave conditions. |
- Core body temperature [ Time Frame: Prior to and throughout each simulated heat wave exposure; an average of 480 minutes. ]Core body temperature will be measured from gastrointestinal temperature via an ingestible telemetric pill.
- Measures of left ventricular function [ Time Frame: Prior to, during, and after each simulated heat wave exposure; approximately 20 min each ]Measures of left ventricular function, such as ventricular wall motion and ventricular filling, will be obtained from echocardiography images.
- Skin temperature [ Time Frame: Prior to and throughout each simulated heat wave exposure; an average of 480 minutes. ]Skin temperature will be measured from small temperature sensitive electrodes attached to the participant's skin
- Heart rate [ Time Frame: Prior to and throughout each simulated heat wave exposure; an average of 480 minutes. ]Heart rate will be measured from ECG electrodes attached to the participant
- Arterial blood pressure [ Time Frame: Prior to and throughout each simulated heat wave exposure; an average of 480 minutes. ]Arterial blood pressure will be measured using a standard arm blood pressure cuff
- Cardiac output [ Time Frame: Prior to, during, and after each simulated heat wave exposure; approximately 20 min each ]Cardiac output (how much blood is ejected from the heart) will be measured using echocardiography and nitrous oxide rebreathing approaches.
- Cerebral perfusion [ Time Frame: Prior to, during, and after each simulated heat wave exposure; approximately 20 min each ]Cerebral perfusion will be measured by doppler ultrasound of the internal carotid and vertebral arteries

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Sampling Method: | Non-Probability Sample |
Inclusion Criteria:
- Healthy male and female individuals
- 18-35 years or 65+ years of age
- Free of any underlying moderate to serious medical conditions
Exclusion Criteria:
- Known heart disease; other chronic medical conditions requiring regular medical therapy including cancer, diabetes, neurological diseases, uncontrolled hypertension, and uncontrolled hypercholesterolemia.
- Taking of any medications (such as beta blockers and non-dihydropyridine calcium channel blockers) that have known influences on either cardiac function or sweating responses.
- Abnormalities detected on routine screening.
- Individuals who participate in a structured aerobic exercise training program at moderate to high intensities.
- Current smokers, as well as individuals who regularly smoked within the past 3 years.
- Body mass index of greater than 30 kg/m^2
- Pregnant individuals

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04538144
Contact: Josh Foster, PhD | 214-345-6504 | joshfoster@texashealth.org | |
Contact: Bonnie Orth, MS | 214-345-4737 | bonnieorth@texashealth.org |
United States, Texas | |
Texas Health Presbyterian Hospital Dallas | Recruiting |
Dallas, Texas, United States, 75231 | |
Contact: Josh Foster, PhD 214-345-6504 joshfoster@texashealth.org | |
Contact: Courtney Hakes, BS RN 214-345-6502 courtneyhakes@texashealth.org | |
Principal Investigator: Craig Crandall, Ph.D. |
Responsible Party: | Craig Crandall, Professor of Medicine, University of Texas Southwestern Medical Center |
ClinicalTrials.gov Identifier: | NCT04538144 |
Other Study ID Numbers: |
STU_2019_1759 |
First Posted: | September 3, 2020 Key Record Dates |
Last Update Posted: | March 1, 2023 |
Last Verified: | February 2023 |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
aging heat wave cardiovascular |
Hyperthermia Body Temperature Changes Heat Stress Disorders Wounds and Injuries |