Skin Surface and Intradermal Temperature Responses to Heat Stress

August 11, 2026 updated by: Craig Crandall, University of Texas Southwestern Medical Center
The purpose of this study is to compare surface and intradermal skin temperature responses to heat stress with and without evaporative and convective cooling.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Humans have important thermoregulatory responses aimed at maintaining body temperature within a narrow range. These responses are driven in part by receptors located in the skin that monitor temperature changes and provide feedback to the central nervous system. Given that skin temperature can affect the physiological responses to heat stress, it is important to accurately measure skin temperature in response to heat stress with and without evaporative (i.e., sweat) and convective (i.e., air flow) cooling. Skin temperature is most often measured on the surface of the skin; however, this temperature can be influenced by other factors such as the local environment. It is unclear how the temperature of the skins surface compares to the temperature within the dermal layer of the skin.

The study team will directly compare skin surface and intradermal temperature responses to heat stress and determine whether these responses area altered by evaporative or convective cooling methods. To accomplish this objective, healthy adults will be exposed to ambient heat stress (no higher than 47°C) with and without evaporative (water sprayed on the skin) and convective (electric fan) cooling. Thermoregulatory responses, inclusive of skin surface and intradermal temperatures, will be assessed throughout the heat trial.

Study Type

Interventional

Enrollment (Actual)

27

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Texas
      • Dallas, Texas, United States, 75231
        • Institute for Exercise and Environmental Medicine

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Free of any significant underlying medical problems based upon a detailed medical history and physical exam.
  • Normal resting electrocardiogram.

Exclusion Criteria:

  • Known heart disease; other chronic medical conditions requiring regular medical therapy including cancer, diabetes, neurological diseases, and uncontrolled hypertension, etc.; as well as serious abnormalities detected on routine screening.
  • Individuals who are pregnant, planning to become pregnant, or breastfeeding.
  • Taking prescribed medications (such as beta blockers and non-dihydropyridine calcium channel blockers) or over-the-counter medications that have known influences on thermoregulatory response.
  • Current smokers, as well as individuals who regularly smoked within the past 3 years.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Intradermal Skin Temperature Needle in Intradermal Skin Layer
Skin temperature measured in the intradermal space
Other: Control
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes without a cooling modality.
Other: Fan
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes with an electric fan as a cooling modality.
Other: Fan and Water Spray
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes with an electric fan and water spray as cooling modalities.
Other: Water Spray
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes with water spray as a cooling modality.
Active Comparator: Intradermal Skin Temperature Needle on Skin Surface
Skin temperature measured on the skin's surface using the same type of probe as that used in the intradermal space.
Other: Control
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes without a cooling modality.
Other: Fan
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes with an electric fan as a cooling modality.
Other: Fan and Water Spray
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes with an electric fan and water spray as cooling modalities.
Other: Water Spray
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes with water spray as a cooling modality.
Active Comparator: Skin Temperature Thermocouple on Skin Surface
Skin temperature measured on the skin's surface using a standard temperature probe
Other: Control
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes without a cooling modality.
Other: Fan
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes with an electric fan as a cooling modality.
Other: Fan and Water Spray
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes with an electric fan and water spray as cooling modalities.
Other: Water Spray
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes with water spray as a cooling modality.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Skin Temperature With Fan Only
Time Frame: 40 minutes into the heat intervention.
Skin temperature will be measured from small temperature sensitive electrodes attached to the surface and intradermal layer of the skin of the participant with the fan cooling modality.
40 minutes into the heat intervention.
Skin Temperature With Fan and Water Spray
Time Frame: 60 minutes into the heat intervention.
Skin temperature will be measured from small temperature sensitive electrodes attached to the surface and intradermal layer of the skin of the participant with both the fan and water spray cooling modalities.
60 minutes into the heat intervention.
Skin Temperature With Water Spray Only
Time Frame: 1 hour 20 minutes into the the heat intervention.
Skin temperature will be measured from small temperature sensitive electrodes attached to the surface and intradermal layer of the skin of the participant with the water spray cooling modality.
1 hour 20 minutes into the the heat intervention.
Skin Temperature With No Cooling
Time Frame: 20 minutes into the heat intervention.
Skin temperature will be measured from small temperature sensitive electrodes attached to the surface and intradermal layer of the skin of the participant during the heat intervention with no cooling.
20 minutes into the heat intervention.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Texas Southwestern Medical Center

Investigators

  • Principal Investigator: Craig Crandall, Ph.D., University of Texas Southwestern Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 1, 2024

Primary Completion (Actual)

November 13, 2025

Study Completion (Actual)

November 13, 2025

Study Registration Dates

First Submitted

September 6, 2024

First Submitted That Met QC Criteria

September 9, 2024

First Posted (Actual)

September 19, 2024

Study Record Updates

Last Update Posted (Actual)

August 14, 2026

Last Update Submitted That Met QC Criteria

August 11, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STU_2024_0636

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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