Heat Waves and the Elderly - Cooling Modalities

NCT05484739 | Recruiting DMC

• 1 other identifier: STU-2022-0625
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

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

Conditions

Aging; Hyperthermia

Keywords

aging; heat wave; cardiovascular; low-energy cooling

Outcome Measures

Primary Outcomes (2)

• Change in core body temperature

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

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

• Change in left ventricular function

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

  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

Secondary Outcomes (12)

• Heart rate

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

• Cardiac output

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

• Arterial blood pressure

  Prior to and throughout each simulated heat wave exposure; an average of 480 minutes

• Whole body sweat rate

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

• Markers of renal function and injury - Cystatin C

  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

Study Arms (2)

Very hot and dry

EXPERIMENTAL

Subjects will be exposed to 3 hours in a climate chamber set to approximately 47 deg C and 15% relative humidity, which reflects a very hot and dry heat wave condition similar to the 2018 Los Angeles heat wave. Four visits will be required to complete this arm, with each visit a different cooling modality applied.

Other: Water Spray; Other: Fan; Other: Water Spray and Fan; Other: Control

Hot and humid

EXPERIMENTAL

Subjects will be exposed to 3 hours in a climate chamber set to approximately 41 deg C and 40% relative humidity, which reflects hot and humid heat wave similar to the 1995 Chicago heat wave. Four visits will be required to complete this arm, with each visit a different cooling modality applied.

Other: Water Spray; Other: Fan; Other: Water Spray and Fan; Other: Control

Interventions

Water Spray OTHER

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

Hot and humid; Very hot and dry

Fan OTHER

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

Hot and humid; Very hot and dry

Water Spray and Fan OTHER

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

Hot and humid; Very hot and dry

Control OTHER

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

Hot and humid; Very hot and dry

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

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

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Texas Southwestern Medical Center: lead

Study Sites (1)

Texas Health Presbyterian Hospital Dallas

Dallas, Texas, 75231, United States

RECRUITING

MeSH Terms

Conditions

Hyperthermia

Interventions

CCP110 protein, human

Condition Hierarchy (Ancestors)

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

Central Study Contacts

Rachel Cottle, PhD

CONTACT

214-345-6557; RachelCottle@texashealth.org

Erin Harper, BS

CONTACT

214-345-5022; ErinHarper@texashealth.org

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Internal Medicine

Model Details: The investigators will conduct a randomized crossover design study. Older individuals will be exposed to one of two heat wave conditions (Very hot and dry or hot and humid). For each heat wave condition the individual will receive one of the following cooling strategies, with each cooling strategy applied on a different day: A) a control trial, B) skin wetting only trial, C) fan only trial, and D) a combination of skin wetting with a fan trial. Thus, to complete the trial for a selected heat wave condition (e.g., either very hot and dry or hot and humid) four experimental visits will be required - one visit for each cooling strategy.

Study Record Dates

• First Submitted: July 27, 2022
• First Posted: August 2, 2022
• Study Start: February 21, 2023
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): August 31, 2026
• Last Updated: October 23, 2025

Record last verified: 2025-10

Locations

US (1)