Cold-water ImmersionNCT07201935
Thermodynamic Exposure and Sleep in Military Cadets
A study testing Cold Water Immersion and High Heat Sauna in people with Cold-water Immersion and High Heat Sauna, run by Medical University of South Carolina at 1 site in United States.
Trial summary
This pilot study investigates the effects of cold-water immersion, traditional sauna use, and their combination on sleep architecture and psychological health in military cadets. The study uses wearable technologies including the Oura Ring to collect objective sleep and physiological data. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Cold-water Immersion, High Heat Sauna, Combination of Cold-water Immersion and High Heat Sauna
- What is being tested?
- Cold Water Immersion and High Heat Sauna
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 45 participants
- Where
- 1 siteUnited States
- Study dates
- Oct 2026to May 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
- Inclusion Criteria
- 18 - 30 years of age
- Enrolled military cadet at the Citadel Military College.
- Access to a smartphone with access to appropriate app marketplace (Apple iOS 15, Android 8.0 or newer) and reliable data access.
- Ability to access and operate Oura Ring application.
- Exclusion Criteria
- Medical contraindications to continuous wearing of the Oura Ring.
- Current diagnosis of neurological conditions that impact vascular blood flow or the individual's ability to regulate temperature.
- History of cardio-vascular conditions or history of poor blood circulation.
- History of heat stroke or known sensitivity to hot/cold environments.
- Currently taking medications that impair fluid balance, thermoregulation, blood flow, respiration, or heart rate.
- Known dermatological disease aggravated by changes in temperature.
- Pregnant or trying to become pregnant within the study timeframe. Urine samples will be provided by interested female cadets to ensure they are not pregnant.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
The Citadel Military College
Charleston, South Carolina, 29404
Geoffery Mcleod, DO, 843-953-4827, mcleodge@musc.edu
About this study
Official title: Hot, Cold, and Combined Thermodynamic Exposure to Improve Sleep Quality Among Military Cadets
This pilot study investigates the effects of cold-water immersion, traditional sauna use, and their combination on sleep architecture and psychological health in military cadets. The study uses wearable technologies including the Oura Ring to collect objective sleep and physiological data.
Read the detailed description
The study will enroll 45 military cadets from The Citadel Military College, randomized into three groups: Cold-Water Immersion (CWI), High Heat Sauna (HHS), and Combined (COM). Participants will undergo a 7-day baseline period followed by a 14-day intervention. Sleep architecture and psychological-affective health will be assessed using validated wearable devices and questionnaires. The study aims to identify intervention-specific improvements in sleep and psychological health.
- Conditions
- Cold-water Immersion, High Heat Sauna, Combination of Cold-water Immersion and High Heat Sauna
- Being tested
- Cold Water Immersion, High Heat Sauna
- Keywords
- Sleep quality, Sleep architecture, Thermodynamic exposure
- Medical subject headings
- Sleep Initiation and Maintenance Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cold Water ImmersionBehavioural
Participants will complete 14 daily sessions of cold-water immersion exposure.
High Heat SaunaBehavioural
Participants will complete 14 evening sessions in the high heat sauna
| Study group | Role | What they receive |
|---|---|---|
| Cold-water immersion | Experimental | 5 minutes of cold-water immersion (submerged up to chin) at 8 - 10C°(46.4 - 50F°) in the morning between 6:00 - 8:00am. Receives: Behavioral: Cold Water Immersion |
| High heat sauna | Experimental | 20 minutes of high heat sauna at 90 - 94C° (190 - 201.2F°) between 5:00 - 7:00pm Receives: Behavioral: High Heat Sauna |
| Combination | Experimental | 5 minutes of cold-water immersion (submerged up to chin) at 8 - 10C°(46.4 - 50F°) in the morning between 6:00 - 8:00am and 20 minutes of high heat sauna at 90 - 94C° (190 - 201.2F°) between 5:00 - 7:00pm Receives: Behavioral: Cold Water Immersion; Behavioral: High Heat Sauna |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sleep Efficiency
Percentage of sleep period spent asleep measured by the Oura Ring (percentage, %)
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Pittsburgh Sleep Quality Index
Self-reported sleep quality
Measured: At the end of the baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention phase (Day 28)
Brief Mood Introspection Scale
Self-reported assessment of mood consisting of 16 mood adjectives. Participants rate each adjective on a 4-point likert scale (1 = definitely don't feel, 4 = definitely feel). The scale uses a combination of direct and reverse scoring so that higher scores reflect more favorable mood states (max = 64).
Measured: At the end of the baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention phase (Day 28)
Secondary outcomes (9)
Total Sleep Duration
Total duration of sleep period measured by the Oura Ring (seconds, s)
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
REM Sleep Duration
Duration of sleep period spent in REM sleep measured by the Oura Ring (seconds, s)
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Deep Sleep Duration
Duration of sleep periods spent in deep (N3) sleep (seconds, s)
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Light Sleep Duration
Duration of sleep period spent in light (N1 or N2) sleep (seconds, s)
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Restless Sleep Duration
Duration of sleep period with increased registered movements as measured by the Oura Ring (seconds, s)
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Wake After Sleep Onset (WASO) Duration
Total time spent awake after falling asleep (seconds, s)
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
RMSSD
Root mean squared of temporal latency between successive heart beats throughout sleep period measured by the Oura Ring (milliseconds, ms)
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Nighttime Skin Temperature
Skin temperature (degrees Celsius, C°) throughout sleep period measured by the Oura Ring.
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Sleep Time Heart Rate
Average heart rate during sleep (beats per minute, bpm)
Measured: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Oct 2025
- Study startOct 2026 (estimated)
- Primary completionJan 2027 (estimated)
- Study completionMay 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cold-water ImmersionStudies of the same condition, open and under way.
- More trials run by Medical University of South CarolinaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 45 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medical University of South Carolina
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mark Rosenberg, Medical University of South Carolina
- Investigators
- Mark Rosenberg, MD, Principal investigator, Medical University of South Carolina
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07201935
- Sponsor's protocol ID
- Pro00147353
- Status last verified
- Aug 2026
- First submitted
- 12 Sep 2025
- Last updated
- 1 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 1 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hot, Cold, and Combined Thermodynamic Exposure to Improve Sleep Quality Among Military Cadets
- ClinicalTrials.gov ID
- NCT07201935
- Acronym / sponsor ID
- Pro00147353
- Conditions
- Cold-water Immersion, High Heat Sauna, Combination of Cold-water Immersion and High Heat Sauna
- Keywords
- Sleep quality, Sleep architecture, Thermodynamic exposure
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 45 participants (estimated)
- Lead sponsor
- Medical University of South CarolinaUniversity, hospital or other
- Study start
- Oct 2026 (estimated)
- Primary completion
- Jan 2027 (estimated)
- Study completion
- May 2027 (estimated)
- First posted
- 1 Oct 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This pilot study investigates the effects of cold-water immersion, traditional sauna use, and their combination on sleep architecture and psychological health in military cadets. The study uses wearable technologies including the Oura Ring to collect objective sleep and physiological data.
Detailed description
The study will enroll 45 military cadets from The Citadel Military College, randomized into three groups: Cold-Water Immersion (CWI), High Heat Sauna (HHS), and Combined (COM). Participants will undergo a 7-day baseline period followed by a 14-day intervention. Sleep architecture and psychological-affective health will be assessed using validated wearable devices and questionnaires. The study aims to identify intervention-specific improvements in sleep and psychological health.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Cold-water immersion | Experimental | Behavioral: Cold Water Immersion5 minutes of cold-water immersion (submerged up to chin) at 8 - 10C°(46.4 - 50F°) in the morning between 6:00 - 8:00am. |
| High heat sauna | Experimental | Behavioral: High Heat Sauna20 minutes of high heat sauna at 90 - 94C° (190 - 201.2F°) between 5:00 - 7:00pm |
| Combination | Experimental | Behavioral: Cold Water Immersion, Behavioral: High Heat Sauna5 minutes of cold-water immersion (submerged up to chin) at 8 - 10C°(46.4 - 50F°) in the morning between 6:00 - 8:00am and 20 minutes of high heat sauna at 90 - 94C° (190 - 201.2F°) between 5:00 - 7:00pm |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cold Water ImmersionParticipants will complete 14 daily sessions of cold-water immersion exposure. | Behavioural | Cold-water immersion, Combination |
| High Heat SaunaParticipants will complete 14 evening sessions in the high heat sauna | Behavioural | Combination, High heat sauna |
Primary outcome
Sleep Efficiency
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Percentage of sleep period spent asleep measured by the Oura Ring (percentage, %)
Pittsburgh Sleep Quality Index
Time frame: At the end of the baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention phase (Day 28)
Self-reported sleep quality
Brief Mood Introspection Scale
Time frame: At the end of the baseline monitoring phase (Day 7), end of intervention week 1 (Day 14), and end of intervention phase (Day 28)
Self-reported assessment of mood consisting of 16 mood adjectives. Participants rate each adjective on a 4-point likert scale (1 = definitely don't feel, 4 = definitely feel). The scale uses a combination of direct and reverse scoring so that higher scores reflect more favorable mood states (max = 64).
9 secondary outcomes
Total Sleep Duration
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
REM Sleep Duration
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Deep Sleep Duration
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Light Sleep Duration
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Restless Sleep Duration
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Wake After Sleep Onset (WASO) Duration
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
RMSSD
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Nighttime Skin Temperature
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Sleep Time Heart Rate
Time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Sep 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Mark Rosenberg, MD principal investigator
Medical University of South Carolina
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Cold Water Immersion and High Heat Sauna in people with Cold-water Immersion and High Heat Sauna, run by Medical University of South Carolina at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 1 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sleep Efficiency (time frame: Each night of the baseline monitoring period (7days) and intervention phase (14days)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Sep 2026.