Skin Surface and Intradermal Temperature Responses to Heat Stress

Not Applicable

Recruiting

• Conditions: Hyperthermia
• Interventions: Other: Ambient Heating

• Registration Number: NCT06593067
• Lead Sponsor: University of Texas Southwestern Medical Center

Brief Summary

The purpose of this study is to compare surface and intradermal skin temperature responses to heat stress with and without evaporative and convective cooling.

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 Timeline

• Study First Submitted: 2024-09-06
• Study First Submitted QC: 2024-09-09
• Study First Posted: 2024-09-19
• Study Start: 2024-10-01
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-04
• Last Update Posted: 2024-11-06
• Primary Completion: 2026-10
• Study Completion: 2026-10

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 20

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Healthy Adults Arm	Ambient Heating	Healthy Subject will rest in an environmental chamber that is no hotter than 47°C (117 °F). While in the chamber, the study team will periodically use a water spray to wet subject's skin and turn on an electric fan. During this time, the temperature of skin on arm using a temperature probe placed on the surface of skin and another temperature probe placed within skin (intradermal) will be monitored.

Primary Outcome Measures

Name	Time	Method
Skin Temperature with Fan Only	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.
Skin Temperature with Fan and Water Spray	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.
Skin Temperature with Water Spray Only	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.
Skin Temperature with No Cooling	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.

Trial Locations

Locations (1)

Institute for Exercise and Environmental Medicine; 🇺🇸 Dallas, Texas, United States