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Influence of Wet Clothing on Thermal Protection

The aim of this investigation is to provide guidance for assessing the influence of wet clothing, and its drying time, on body temperature responses during cold air exposure. Twelve healthy and fit adults (men and women aged 18-49) will complete this study. Four cold air exposures (41°F, 180 min) will be randomly conducted, each while wearing a different clothing ensemble that has been saturated by water. During each cold air exposure, you will be asked to rest for 60 min and perform weighted (38.5lbs) treadmill walking for up to 120 min.

Studieöversikt

Detaljerad beskrivning

Participants, in their first visit, will undergo baseline weighted treadmill walking consisting of ~20 min of treadmill walking with a load of 77lbs followed by ~25 min of treadmill walking with a load of 38.5lbs. They will also have their body composition evaluated (DEXA) and be fit for each uniform ensemble. This first laboratory visit will require ~3 hrs.

On separate days, participants will complete 4 experimental trials. After being submerged up to the neck in warm water for two minutes, three of the trials will ask that the participant move to a 41°F air environment, stand with minimal movement for 60 min, complete 60 min of weighted (38.5lb) treadmill walking at 2 mph, and up to 4% grade, and then complete 60 min of weighted (38.5lb) treadmill walking at 2.5 mph and up to 4% grade. Each of these three experimental trial visits will require ~5 hrs.

A single trial will ask that after being saturated in warm water, participants enter a 41°F air environment, immediately begin weighted treadmill walking (38.5lbs) at 2.0mph and up to 4% grade for a duration of 60 min before standing with minimal movement for 60 min. This trial will require ~4 hrs.

During all experimental trials, the primary outcomes include core temperature, measured continuously using a small pill inserted as a rectal suppository, and skin temperature, measured continuously using 11 small skin attached sensors. Secondary outcomes include metabolic rate, heart rate, thermal perceptions, and changes in body mass.

Non-federally employed civilians may be eligible to be paid $13.50/hour for participation (for a total of up to $310).

Studietyp

Interventionell

Inskrivning (Förväntat)

30

Fas

  • Inte tillämpbar

Kontakter och platser

Det här avsnittet innehåller kontaktuppgifter för dem som genomför studien och information om var denna studie genomförs.

Studiekontakt

Studieorter

Deltagandekriterier

Forskare letar efter personer som passar en viss beskrivning, så kallade behörighetskriterier. Några exempel på dessa kriterier är en persons allmänna hälsotillstånd eller tidigare behandlingar.

Urvalskriterier

Åldrar som är berättigade till studier

18 år till 49 år (Vuxen)

Tar emot friska volontärer

Nej

Kön som är behöriga för studier

Allt

Beskrivning

Inclusion Criteria:

  • Military or civilian, male or female, between the ages of 18 (17 if active duty military) and 49 years.
  • Able to carry a rucksack weighing 35 kg (77lbs) for at least 20 minutes and able to carry a rucksack weighing 17.5kg (38.5lbs) for up to 120 minutes
  • In good health as determined by our OMSO (Office of Medical Support and Oversight) General Medical Clearance.
  • Vaccinated against COVID 19.
  • Willing to refrain from heavy exercise and alcoholic beverages for 24 hours before each testing session.
  • Willing to refrain from smoking or tobacco use for 8 hours before each testing session.
  • Willing to refrain from caffeine ingestion for 12 hours before each testing session.
  • Body fat percentage <18% for males, < 24% for females, once 6 individuals of higher body fat (18% or greater for males, 24% or greater for females) have completed the study.

Exclusion Criteria:

  • History of cold injuries.
  • Raynaud's syndrome.
  • Cold-induced asthma/bronchospasm.
  • Medications or dietary supplements that could alter cardiovascular, thermoregulatory, or vascular control.
  • Heart, lung, kidney, muscle, or nerve disorder(s).
  • Planned MRI during or within two days after completing the study.
  • Known allergy to adhesives.
  • Female and pregnant, planning to become pregnant, or breastfeeding.

Studieplan

Det här avsnittet ger detaljer om studieplanen, inklusive hur studien är utformad och vad studien mäter.

Hur är studien utformad?

Designdetaljer

  • Primärt syfte: Övrig
  • Tilldelning: Randomiserad
  • Interventionsmodell: Crossover tilldelning
  • Maskning: Ingen (Open Label)

Vapen och interventioner

Deltagargrupp / Arm
Intervention / Behandling
Experimentell: Improved Hot Weather Combat Uniform
Wearing the Improved Hot Weather Combat Uniform; Asked to perform 60 min of standing with minimal movement, 60 min weighted (38.5lb) treadmill walking at 2.0mph, up to 4% grade, 60 min weight (38.5lb) treadmill walking at 2.5mph, up to 4% grade.
Water-saturated Improved Hot Weather Combat Uniform
Experimentell: Army Combat Uniform
Wearing the Army Combat Uniform; Asked to perform 60 min of standing with minimal movement, 60 min weighted (38.5lb) treadmill walking at 2.0mph, up to 4% grade, 60 min weight (38.5lb) treadmill walking at 2.5mph, up to 4% grade.
Water-saturated Army Combat Uniform
Experimentell: Army Combat Uniform + Silk Weights
Wearing the Army Combat Uniform + a base layer of silk weights; Asked to perform 60 min of standing with minimal movement, 60 min weighted (38.5lb) treadmill walking at 2.0mph, up to 4% grade, 60 min weight (38.5lb) treadmill walking at 2.5mph, up to 4% grade.
Water-saturated Army Combat Uniform + Silk Weights
Experimentell: Army Combat Uniform- XR
Wearing the Army Combat Uniform; Asked to perform 60 min weighted (38.5lb) treadmill walking at 2.0mph, up to 4% grade, followed by 60 min of standing with minimal movement
Water-saturated Army Combat Uniform

Vad mäter studien?

Primära resultatmått

Resultatmått
Åtgärdsbeskrivning
Tidsram
Core Temperature
Tidsram: 5 hours
Core temperature will be measured using a temperature pill that is inserted as a rectal suppository.
5 hours
Skin Temperature
Tidsram: 5 hours
Skin temperature will be measured using 11 different skin-attached temperature sensors.
5 hours

Sekundära resultatmått

Resultatmått
Åtgärdsbeskrivning
Tidsram
Heart Rate
Tidsram: 5 hours
Heart Rate will be measured using telemetry [beats per min]
5 hours
Syreförbrukning/metabolisk värmeproduktion (MHP)
Tidsram: flera 5 minuters samlingar upp till 1 timme
Syreförbrukning och MHP kommer att bedömas med hjälp av datoriserad indirekt kalorimetri [ml/kg/min; Watt per meter i kvadrat]
flera 5 minuters samlingar upp till 1 timme
Thermal Sensation (whole body, feet, and hands)
Tidsram: multiple 1 minute collections up to 1 hour
Thermal sensation will be assessed using the American Society of Heating, Refrigerating and Air-conditioning Engineers Thermal Sensation Scale. This scale has numbers from -4 to +4 with every whole number accompanied by a verbal expression. The verbal expressions are used only to give the subject a relative feeling pertaining to the relative sensation. For example, -4 is associated with very cold whereas +4 is associated with very hot.
multiple 1 minute collections up to 1 hour
Thermal Comfort
Tidsram: multiple 1 minute collections up to 1 hour
Thermal comfort will be assessed using a standard Thermal Comfort Scale. We will ask volunteers to rate how comfortable they feel with respect to temperature sensation. The scale has numbers ranging from 0 to 4 and with descriptors ranging from comfortable (0) to intolerable (4).
multiple 1 minute collections up to 1 hour
Perceived Skin Wetness
Tidsram: multiple 1 minute collections up to 1 hour
Perceived Skin Wetness will be assessed using an adapted Skin Wetness Perception Scale. The scale ranges from 0 (extremely dry) to -6 (extremely wet; soaked).
multiple 1 minute collections up to 1 hour

Samarbetspartners och utredare

Det är här du hittar personer och organisationer som är involverade i denna studie.

Studieavstämningsdatum

Dessa datum spårar framstegen för inlämningar av studieposter och sammanfattande resultat till ClinicalTrials.gov. Studieposter och rapporterade resultat granskas av National Library of Medicine (NLM) för att säkerställa att de uppfyller specifika kvalitetskontrollstandarder innan de publiceras på den offentliga webbplatsen.

Studera stora datum

Studiestart (Faktisk)

2 september 2021

Primärt slutförande (Förväntat)

30 september 2023

Avslutad studie (Förväntat)

30 september 2023

Studieregistreringsdatum

Först inskickad

24 maj 2022

Först inskickad som uppfyllde QC-kriterierna

3 juni 2022

Första postat (Faktisk)

8 juni 2022

Uppdateringar av studier

Senaste uppdatering publicerad (Faktisk)

27 januari 2023

Senaste inskickade uppdateringen som uppfyllde QC-kriterierna

25 januari 2023

Senast verifierad

1 januari 2023

Mer information

Termer relaterade till denna studie

Ytterligare relevanta MeSH-villkor

Andra studie-ID-nummer

  • 21-12H

Plan för individuella deltagardata (IPD)

Planerar du att dela individuella deltagardata (IPD)?

Nej

Läkemedels- och apparatinformation, studiedokument

Studerar en amerikansk FDA-reglerad läkemedelsprodukt

Nej

Studerar en amerikansk FDA-reglerad produktprodukt

Nej

Denna information hämtades direkt från webbplatsen clinicaltrials.gov utan några ändringar. Om du har några önskemål om att ändra, ta bort eller uppdatera dina studieuppgifter, vänligen kontakta register@clinicaltrials.gov. Så snart en ändring har implementerats på clinicaltrials.gov, kommer denna att uppdateras automatiskt även på vår webbplats .

Kliniska prövningar på Low Body Temperatures

3
Prenumerera