Skip to main content
OpenTrials
Recruiting

NCT Number: NCT05484739

Heat Waves and the Elderly - Cooling Modalities

The purpose of this study is to assess how well cooling modalities work in reducing cardiovascular stress of the elderly to heat wave conditions

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Aging Body Temperature Changes Heat Stress Disorders Hyperthermia Pathological Conditions, Signs and Symptoms Signs and Symptoms Wounds and Injuries

Age range

65 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

Heat waves are lethal and cause a disproportionate number of deaths in the elderly relative to any other age group. Such deaths are primarily cardiovascular, not hyperthermia itself, in origin. The central hypothesis of this work is that cardiovascular stress during heat wave conditions in the elderly can be reduced by applying low-energy cooling modalities. Comprehensive cardiovascular and thermal responses in the elderly will be evaluated during exposure to two prolonged heat wave conditions: hot and humid (replicating the 1995 Chicago heat wave), very hot and dry (replicating the 2018 Los Angeles heat wave). With each of these heat wave conditions individuals will be exposed to the following cooling modalities: no cooling (control), water spray, fan use, and fan use plus water spray.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 65 years of age or older
  • Free of any significant underlying medical problems based upon a detailed medical history and physical exam

Exclusion criteria

  • Known heart disease
  • Other chronic medical conditions requiring regular medical therapy including cancer, diabetes, uncontrolled hypertension, and uncontrolled hypercholesterolemia etc;
  • Abnormality detected on routine screening suggestive of provokable ischemia or previously undetected cardiac disease or resting left bundle branch block on screening electrocardiogram.
  • Current smokers, as well as individuals who regularly smoked within the past 3 years
  • Subject with a body mass index ≥31 kg/m2
  • Pregnant individuals

Treatment and study plan

Water Spray

Other

Participants will receive water spraying on their body throughout the climate chamber exposure.

Fan

Other

Participants will be exposed to a fan throughout the climate chamber exposure.

Water Spray and Fan

Other

Participants will receive both water spraying and a fan throughout the climate chamber exposure.

Control

Other

Participants will NOT receive either water spray or a fan exposure.

Primary outcomes

  1. Change in core body temperature

    Time frame: Body core temperature will be obtained within 60 min before the heat wave exposure after the 3 hour heat wave exposure.

    Change in core body temperature will be measured either from a temperature sensor pill or from a rectal thermometer

  2. Change in left ventricular function

    Time frame: Within 60 minutes before each simulated heat wave exposure, around minute 90 of the heat wave exposure, and at the end of the 3 hour heat wave exposure

    Measures of left ventricular function, such as ventricular wall motion and ventricular filling, will be obtained from echocardiography images.

Secondary outcomes

  1. Heart rate

    Time frame: Prior to and throughout each simulated heat wave exposure; approximately 420 minutes

    Heart rate will be measured from ECG electrodes attached to the participant

  2. Cardiac output

    Time frame: Within 60 minutes before each simulated heat wave exposure and during each simulated heat wave exposure (up to 3 hours)

    Cardiac output (how much blood is ejected from the heart) will be measured using 3D echocardiography.

  3. 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.

  4. Whole body sweat rate

    Time frame: Within 60 minutes before each simulated heat wave exposure and within 30 minutes after each heat wave exposure.

    Whole body sweat rate will be measured by through nude weight of the participant.

  5. Markers of renal function and injury - Cystatin C

    Time frame: Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure

    Markers of renal function and injury (e.g., cystatin C) will be evaluated from blood sampling collection.

  6. Markers of renal function and injury - Creatinine Clearance

    Time frame: Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure

    Markers of renal function and injury (e.g., creatinine clearance) will be evaluated from blood sampling and urine collection.

  7. Markers of renal function and injury - Insulin-like growth factor-binding protein 7

    Time frame: Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure

    Markers of renal function and injury (e.g., Insulin-like growth factor-binding protein 7) will be evaluated from urine sampling.

  8. Markers of renal function and injury - Tissue inhibitor of metalloproteinases 2

    Time frame: Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure

    Markers of renal function and injury (e.g., Tissue inhibitor of metalloproteinases 2) will be evaluated from urine sampling.

  9. Cerebral perfusion

    Time frame: Within 60 minutes before each simulated heat wave exposure and during each simulated heat wave exposure (up to 3 hours)

    Cerebral perfusion will be measured by Doppler ultrasound of the internal carotid and vertebral arteries.

  10. High sensitive cardiac troponin

    Time frame: Within 60 minutes before each simulated heat wave exposure, during each simulated heat wave exposure (up to 3 hours), and within 2 hours after the simulated heat wave exposure

    A plasma-based marker of cardiac stress (high sensitive cardiac troponin) be evaluated from blood sampling.

  11. Skin temperature

    Time frame: Within 60 minutes before each simulated heat wave exposure and during each simulated heat wave exposure (up to 3 hours)

    Skin temperature will be measured from small temperature sensitive electrodes attached to the participant's skin

  12. Forced vital capacity (FVC)

    Time frame: Within 60 minutes before each simulated heat wave exposure and during each simulated heat wave exposure (up to 3 hours)

    Forced vital capacity will be obtained from spirometry

Study contacts

Contact information is provided by the study sponsor or research team.

Erin Harper, BS

CONTACT

[email protected]

214-345-5022

Rachel Cottle, PhD

CONTACT

[email protected]

214-345-6557

Sponsors and collaborators

Lead sponsor

University of Texas Southwestern Medical Center

Other

Registry information

Official study title

Heat Waves in the Elderly: Reducing Thermal and Cardiovascular Consequences

Important dates

Study start
2023
Primary completion
2026
Study completion
2026
First posted
Aug 2, 2022
Registry last updated
Oct 23, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.