NCT07433036

Brief Summary

This study will help us as scientists and clinicians understand how effective commonly used cooling protocols in emergency departments are and which of the protocols is the most effective. It consists of a single, approximately 1 hour preliminary session and five, approximately 3 hour experimental sessions, equaling an approximate 16 hour total time commitment. The purpose of this research is to test the effectiveness of three cooling protocols.

  1. 1.Cooling packs
  2. 2."Ice Sheets", which are bed sheets soaked in ice water, wrapped around the participant, while a fan blows air on them.
  3. 3.Body bag filled with ice, commonly used in emergency departments to treat hyperthermia

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
50

participants targeted

Target at P25-P50 for not_applicable

Timeline
31mo left

Started Jul 2025

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress27%
Jul 2025Dec 2028

Study Start

First participant enrolled

July 1, 2025

Completed
7 months until next milestone

First Submitted

Initial submission to the registry

February 10, 2026

Completed
15 days until next milestone

First Posted

Study publicly available on registry

February 25, 2026

Completed
1.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2027

Expected
1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2028

Last Updated

February 25, 2026

Status Verified

February 1, 2026

Enrollment Period

2.5 years

First QC Date

February 10, 2026

Last Update Submit

February 18, 2026

Conditions

Keywords

HyperthermiaExercise

Outcome Measures

Primary Outcomes (1)

  • Rectal temperature cooling rate

    Following termination of the exercise protocol, at a core temperature above 39 degrees Celcius, participants will be cooled until they reach a core temperature of 38 degrees Celcius. The cooling rate in degrees Celcius per minute, is the primary outcome.

    The measurement occurs immediately upon completion of the exercise protocol. Time itself is part of the outcome variable and will vary between participants (~3 to 40 min post exercise protocol).

Study Arms (5)

Passive cooling

ACTIVE COMPARATOR

Participant lies supine in an air-conditioned room

Procedure: Passive cooling

Cooling packs

EXPERIMENTAL

During recovery, cooling packs are applied on either side of the neck, both underarms, and both sides of the groin

Procedure: Cooling packs

Ice sheets

EXPERIMENTAL

During recovery, participants lie supine and are wrapped in bed sheets that have been soaked in ice water, then have a fan directed towards them while cooling

Procedure: Ice sheets

Body bag full of ice

EXPERIMENTAL

During recovery, participants are zipped into a body bag that is full of ice

Procedure: Body bag cooling

Cold water immersion

EXPERIMENTAL

During recovery, participants are submerged to the neck in a cold water bath

Procedure: Cold water immersion

Interventions

During recovery, participants lie supine in an air-conditioned room

Passive cooling
Cooling packsPROCEDURE

During recovery, participants lie supine while ice packs are applied to both sides of the neck, both arm pits, and both sides of the groin

Also known as: Ice packs
Cooling packs
Ice sheetsPROCEDURE

During recovery, participants are wrapped in bed sheets that have been soaked in ice water, while an electric fan blows air across their body

Ice sheets

During recovery, participants are placed in a body bag full of ice, and then have ice placed on top of their body, followed by zipping the body bag closed.

Also known as: Ice bag
Body bag full of ice

During recovery, participants are submerged in a bath, up to their neck, in cold water water with ice

Also known as: Ice water immersion
Cold water immersion

Eligibility Criteria

Age18 Years - 65 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Active, healthy individuals

You may not qualify if:

  • Pregnant or planning on becoming pregnant
  • Have a pacemaker
  • Currently taking any prescribed or over the counter medications or nutritional supplements known to influence thermoregulatory responses
  • Experience lingering pain from a previous musculoskeletal injury (i.e. knee, hip, or back pain)
  • Use tobacco/nicotine products

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Colorado Colorado Springs

Colorado Springs, Colorado, 80918, United States

RECRUITING

MeSH Terms

Conditions

HyperthermiaMotor Activity

Interventions

Ice Cover

Condition Hierarchy (Ancestors)

Body Temperature ChangesSigns and SymptomsPathological Conditions, Signs and SymptomsHeat Stress DisordersWounds and InjuriesBehavior

Intervention Hierarchy (Ancestors)

Geological PhenomenaPhysical PhenomenaIceEnvironmentEcological and Environmental PhenomenaBiological PhenomenaEnvironment and Public Health

Central Study Contacts

Nathan Morris, PhD

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Assistant professor

Study Record Dates

First Submitted

February 10, 2026

First Posted

February 25, 2026

Study Start

July 1, 2025

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

December 31, 2028

Last Updated

February 25, 2026

Record last verified: 2026-02

Data Sharing

IPD Sharing
Will not share

Locations