Recruiting

Cooling Modalities

Sponsor:

University of Texas Southwestern Medical Center

Code:

NCT06961929

Conditions

Heart Failure

Hyperthermia

Eligibility Criteria

Sex: All

Age: 45+

Healthy Volunteers: Accepted

Interventions

Control Trial

Water-saturated T-shirt trial

Skin-Wetting Trial

Study Details

Brief summary:

We will test the hypothesis that increasing skin wetness, and thus evaporative cooling, will attenuate the increase in core body temperature and accompanying cardiac stress during heat wave conditions in individuals with congestive heart failure. Secondly, we propose that wearing a water-saturated T-shirt will also be beneficial to attenuate the increase in core body temperature and accompanying cardiac stress during heat wave conditions in individuals with congestive heart failure. To accomplish these objectives, individuals with congestive heart failure and otherwise healthy control individuals will be exposed to the simulated heat wave condition (hot and dry) with the following cooling modalities: A) control trial (no limb immersion or skin wetting), B) skin wetting only trial, and C) water-saturated T-shirt trial in a randomized crossover fashion. Thermoregulatory and cardiovascular responses will be evaluated throughout these simulated heat wave exposures.

Primary outcomes variables will be skin and core temperatures, while secondary variables will include measures of cardiovascular stress, myocardial perfusion, heart rate, and echo-based measures of cardiac function.

Conditions

Heart Failure

Hyperthermia

Study ID

NCT06961929

Start date

Oct 1, 2025

Status verified date

May, 2026

Completion date

Jul 1, 2030

Anticipated

Primary completion date

Jul 1, 2030

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 45+

Healthy Volunteers: Accepted

Inclusion Criteria for healthy control participants:

  • Participants must be free of any significant underlying medical problems based upon a detailed medical history and physical exam, and normal resting electrocardiogram. Participants must be 45+ years.

Exclusion Criteria for healthy control participants:

  • Known heart disease; other chronic medical conditions requiring regular medical therapy including cancer, diabetes, neurological diseases, and uncontrolled hypertension, lung disease, etc.; as well as serious abnormalities detected on routine screening. Current smokers, as well as individuals who regularly smoked within the past 12 months, will be excluded. Subjects who cannot be age and gender matched to an individual in the heart failure group will be excluded.

Inclusion Criteria for Participants with CHF:

\- The participant must have a diagnosis of congestive heart failure (e.g., heart failure with reduced ejection fraction), with the severity categorized as New York Heart Association (NYHA) class II or III. Participants must be 45+ years.

Exclusion Criteria for Participants with CHF:

-Patients who do not have confirmed diagnosis of NYHA class II or III heart failure will be excluded from the clinical group. Potential participants with cancer, diabetes, neurological disease, lung disease, and/or uncontrolled hypertension will be excluded. Potential participants with a left bundle branch block on ECG will be excluded. Patients on anticoagulant therapy will also be excluded. Current smokers, as well as individuals who regularly smoked within the past 12 months, will be excluded. Further exclusions will include severe valvular or congenital heart disease, acute myocarditis, NYHA Class IV heart failure, and/or manifest/provocable ischemic heart disease.

Study Design

Enrollment

88 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

active comparator: Individuals with Congestive Heart Failure (CHF)

active comparator: Individuals without Congestive Heart Failure (Control)

Interventions

Control Trial

All participants will be exposed to a period of hyperthermia (hot and dry). In this condition, participants will not be given an experimental cooling modality.

Water-saturated T-shirt trial

All participants will be exposed to a period of hyperthermia (hot and dry). In this condition, participants will also wear a T-shirt that has been saturated with water.

Skin-Wetting Trial

All participants will be exposed to a period of hyperthermia (hot and dry). In this condition, participants will also be sprayed with water periodically.

Primary outcome measure

  • Change in Core Body Temperature while wearing a water-saturated T-shirt [ Time Frame: Prior to and after each simulated heat wave exposure (approximately 210 minutes.) ]
  • Change in Core Body Temperature in Skin-Wetting Trial [ Time Frame: Prior to and after each simulated heat wave exposure (approximately 210 minutes.) ]
  • Change in Core Body Temperature in Control Trial [ Time Frame: Prior to and after each simulated heat wave exposure (approximately 210 minutes.) ]
  • Change in Skin Temperature in while wearing a water-saturated T-shirt [ Time Frame: Prior to and after each simulated heat wave exposure (approximately 210 minutes.) ]
  • Change in Skin Temperature in Skin-Wetting Trial [ Time Frame: Prior to and after each simulated heat wave exposure (approximately 210 minutes.) ]
  • Change in Skin Temperature in Control Trial [ Time Frame: Prior to and after each simulated heat wave exposure (approximately 210 minutes.) ]

Central Contacts and Locations

Central contacts

Craig Crandall, PhD

214-345-4623craigcrandall@texashealth.org

Rachel Cottle, PhD

214-345-4737rachelcottle@texashealth.org

Locations

Institute for Exercise and Environmental Medicine - Texas Health Presbyterian Hospital Dallas

Recruiting

Dallas, Texas, United States, 75231

Contacts

Erin M Harper, B.S.

214-345-4737erinharper@texashealth.org

Craig G Crandall, PhD

214-345-4623craigcrandall@texashealth.org

More Information

Sponsor

University of Texas Southwestern Medical Center

Last update posted

May 26, 2026

Last verified

May, 2026

Keywords

  • heat wave
  • cardiovascular
  • cooling strategies
  • myocardial perfusion

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by University of Texas Southwestern Medical Center on 2026-05-26.