Hyperthermia
Conditions
Keywords
Skin Temperature, Intradermal Temperature, Cooling Modalities
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.
Interventions
OTHERControl
Individuals will be exposed to a heated environment (41°C, 15% humidity) for a period of 15 minutes without a cooling modality.
OTHERFan
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.
OTHERFan 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.
OTHERWater 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.
Sponsors
University of Texas Southwestern Medical Center
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORCraig Crandall, Ph.D.
University of Texas Southwestern Medical Center
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 27 Participants |
| Age, Continuous | 29 years STANDARD_DEVIATION 4 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 24 Participants |
| Region of Enrollment United States | 9 participants |
| Sex: Female, Male Female | 4 Participants |
| Sex: Female, Male Male | 5 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 9 | 0 / 9 | 0 / 9 |
| other Total, other adverse events | 0 / 9 | 0 / 9 | 0 / 9 |
| serious Total, serious adverse events | 0 / 9 | 0 / 9 | 0 / 9 |
Outcome results
None listed