Cold Exposure, Hypothermia, Thermal Insulation, Immersion Suits, Submarine EvacuationNCT06992050
Comparative Evaluation of the Thermal Protection Provided by Submarine Rescue Suits: Half Suit Versus Full Suit
An observational study of Cold Exposure, Hypothermia, Thermal Insulation, Immersion Suits, Submarine Evacuation, run by Medical Corps, Israel Defense Force at 1 site in Israel.
Trial summary
This study evaluated the thermal and functional performance of full-body versus half-body Submarine Escape Immersion Equipment (SEIE) suits during cold water immersion (~16.5°C) and raft sitting. Twenty submariners were divided into two groups. Read more about this study
- Who is it for?
- Ages 18 to 35 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Cold Exposure, Hypothermia, Thermal Insulation, Immersion Suits, Submarine Evacuation
- What is being tested?
- Submariner suit
- Type of treatment
- Medical device
- How many people
- 20 participants
- Where
- 1 siteIsrael
- Study dates
- 1 Mar 2018to 1 Dec 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
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 35 years
- Men only
- Healthy volunteers accepted
- Adult
Study population: The study population consists of healthy, active-duty male submariners from the Israeli Navy, aged 20 to 25 years. All participants were volunteers with no prior acclimatization to cold water or cold environments. Each participant underwent a medical screening by a qualified physician to confirm eligibility and provided written informed consent prior to participation. The cohort was selected to represent operationally relevant individuals likely to utilize Submarine Escape Immersion Equipment (SEIE) suits in real-world scenarios.
Who may be able to join
- Healthy active-duty submariners
- Male participants aged 20-25 years
- No history of cardiovascular, respiratory, or neurological disorders
- Not acclimatized to cold environments or cold water exposure
- Provided written informed consent
- Medically cleared for cold water immersion by a physician prior to participation -
Who cannot join
- History of cardiovascular, respiratory, metabolic, neurological, or musculoskeletal disorders
- Regular exposure to cold environments or cold water (cold-acclimatized individuals)
- Use of medications that could affect thermoregulation or neuromuscular function
- Any skin conditions that may be aggravated by cold water immersion
- Inability to provide informed consent
- Failure to pass pre-exposure medical examination by a study physician
- -
Trial locations and contacts
1 site in 1 country.
About this study
This study evaluated the thermal and functional performance of full-body versus half-body Submarine Escape Immersion Equipment (SEIE) suits during cold water immersion (~16.5°C) and raft sitting. Twenty submariners were divided into two groups.
Read the detailed description
This study investigates the performance of full-body versus half-body Submarine Escape Immersion Equipment (SEIE) suits under conditions simulating submarine emergencies in cold water (~16.5°C). In such scenarios, rapid evacuation and prolonged exposure to cold water pose significant risks of hypothermia and impaired physical function. The aim was to assess and compare the thermal insulation and motor performance effects of both suit designs during water immersion and raft sitting.
Twenty healthy active-duty submariners (age 22 ± 1 years) participated, divided evenly into two groups (full suit vs. half suit). Core temperature was monitored using ingestible sensors, and subjective cold sensation was assessed regularly throughout immersion and raft sitting. Additional outcome measures included fine motor dexterity (assembling shackles) and handgrip strength, recorded before and after exposure.
The experimental protocol involved one session per participant. Anthropometric data were collected, and subjects underwent a controlled immersion and raft sitting protocol using calibrated thermal equipment. Motor function tasks were standardized and repeated to control for learning effects. Statistical analysis included non-parametric repeated measures tests with appropriate corrections for multiple comparisons.
- Being tested
- Submariner suit
- Medical subject headings
- Hypothermia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Submariner suitDevice
Participants wearing full-body Submarine Escape Immersion Equipment (SEIE) suits
| Study group | Role | What they receive |
|---|---|---|
| Full Suit Group | Participants wearing full-body Submarine Escape Immersion Equipment (SEIE) suits Receives: Device: Submariner suit | |
| Half Suit Group | Participants wearing half-body Submarine Escape Immersion Equipment (SEIE) suits Receives: Device: Submariner suit |
What is being measured
The primary outcome is the main question the study is designed to answer.
Core temperature
Core temp. measured with telemetric pills
Measured: two hours
Secondary outcomes (1)
Subjective cold sensation -
Assessed using a standardized cold discomfort scale during immersion and raft sitting.
Measured: two hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 May 2025
- Study start1 Mar 2018
- Primary completion1 Dec 2024
- Study completion1 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cold Exposure, Hypothermia, Thermal Insulation, Immersion Suits, Submarine EvacuationStudies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medical Corps, Israel Defense Force
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dror Ofir, Medical Corps, Israel Defense Force
- Investigators
- Oren GABAY, MD, Principal investigator, ISRAEL NAVAL MEDICAL INSTITUTE
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06992050
- Sponsor's protocol ID
- 1895 - 2018
- Status last verified
- May 2025
- First submitted
- 19 May 2025
- Last updated
- 28 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The raw, de-identified data collected during the study will be made available upon reasonable request. The dataset contains no personally identifiable information and includes only aggregated physiological and performance measurements. Data will be shared for academic, scientific, or regulatory purposes following review and approval by the principal investigator. Requests can be directed to the corresponding author.
Study at a glance
From the registry record, last updated by the sponsor on 28 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparative Evaluation of the Thermal Protection Provided by Submarine Rescue Suits: Half Suit Versus Full Suit
- ClinicalTrials.gov ID
- NCT06992050
- Acronym / sponsor ID
- 1895 - 2018
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Medical Corps, Israel Defense ForceUniversity, hospital or other
- Study start
- 1 Mar 2018 (actual)
- Primary completion
- 1 Dec 2024 (actual)
- Study completion
- 1 Dec 2024 (actual)
- First posted
- 28 May 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 study evaluated the thermal and functional performance of full-body versus half-body Submarine Escape Immersion Equipment (SEIE) suits during cold water immersion (~16.5°C) and raft sitting. Twenty submariners were divided into two groups.
Detailed description
This study investigates the performance of full-body versus half-body Submarine Escape Immersion Equipment (SEIE) suits under conditions simulating submarine emergencies in cold water (~16.5°C). In such scenarios, rapid evacuation and prolonged exposure to cold water pose significant risks of hypothermia and impaired physical function. The aim was to assess and compare the thermal insulation and motor performance effects of both suit designs during water immersion and raft sitting.
Twenty healthy active-duty submariners (age 22 ± 1 years) participated, divided evenly into two groups (full suit vs. half suit). Core temperature was monitored using ingestible sensors, and subjective cold sensation was assessed regularly throughout immersion and raft sitting. Additional outcome measures included fine motor dexterity (assembling shackles) and handgrip strength, recorded before and after exposure.
The experimental protocol involved one session per participant. Anthropometric data were collected, and subjects underwent a controlled immersion and raft sitting protocol using calibrated thermal equipment. Motor function tasks were standardized and repeated to control for learning effects. Statistical analysis included non-parametric repeated measures tests with appropriate corrections for multiple comparisons.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Full Suit Group | – | Device: Submariner suitParticipants wearing full-body Submarine Escape Immersion Equipment (SEIE) suits |
| Half Suit Group | – | Device: Submariner suitParticipants wearing half-body Submarine Escape Immersion Equipment (SEIE) suits |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- The study population consists of healthy, active-duty male submariners from the Israeli Navy, aged 20 to 25 years. All participants were volunteers with no prior acclimatization to cold water or cold environments. Each participant underwent a medical screening by a qualified physician to confirm eligibility and provided written informed consent prior to participation. The cohort was selected to represent operationally relevant individuals likely to utilize Submarine Escape Immersion Equipment (SEIE) suits in real-world scenarios.
Key inclusion criteria (6 listed)
- Healthy active-duty submariners
- Male participants aged 20-25 years
- No history of cardiovascular, respiratory, or neurological disorders
- Not acclimatized to cold environments or cold water exposure
- Provided written informed consent
Key exclusion criteria (7 listed)
- History of cardiovascular, respiratory, metabolic, neurological, or musculoskeletal disorders
- Regular exposure to cold environments or cold water (cold-acclimatized individuals)
- Use of medications that could affect thermoregulation or neuromuscular function
- Any skin conditions that may be aggravated by cold water immersion
- Inability to provide informed consent
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 |
|---|---|---|
| Submariner suitParticipants wearing full-body Submarine Escape Immersion Equipment (SEIE) suits | Device | Full Suit Group, Half Suit Group |
Primary outcome
Core temperature
Time frame: two hours
Core temp. measured with telemetric pills
1 secondary outcome
Subjective cold sensation -
Time frame: two hours
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 May 2025.
- Individual participant dataSharing planned: No. The raw, de-identified data collected during the study will be made available upon reasonable request. The dataset contains no personally identifiable information and includes only aggregated physiological and performance measurements. Data will be shared for academic, scientific, or regulatory purposes following review and approval by the principal investigator. Requests can be directed to the corresponding author.
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. This study is not recruiting at the moment.
Oren GABAY, MD principal investigator
ISRAEL NAVAL MEDICAL INSTITUTE
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Cold Exposure, Hypothermia, Thermal Insulation, Immersion Suits, Submarine Evacuation, run by Medical Corps, Israel Defense Force at 1 site in Israel.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 7 exclusion criteria. 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: finished, as of the sponsor's last update on 28 May 2025. 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 Israel. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Core temperature (time frame: two hours). 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 28 May 2025.