Sick LeaveNCT04130126
Feasibility and Effects of Taking Cold Showers: A Randomized Controlled Study
A study testing Taking cold showers in people with Sick Leave, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.
Trial summary
Considering the beneficial individual and environmental effects, investigators set out to replicate the recent study on the effects of taking cold showers on sickness absence, illness days and subjective well-being and to assess both the acceptability of taking cold showers as well as its effects on sickness absence… Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Sick Leave
- What is being tested?
- Taking cold showers
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 350 participants
- Where
- 1 siteSwitzerland
- Study dates
- 26 Oct 2021to 31 Dec 2023
- Phase
- Interventional
- 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 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- healthy participants between 18 and 65 years of age
- no cold shower taken on a regular basis by participants
Who cannot join
- pregnant or lactating women
- subjects with cardiac, pulmonary or any other severe disease by self-report.
Trial locations and contacts
1 site in 1 country.
About this study
Considering the beneficial individual and environmental effects, investigators set out to replicate the recent study on the effects of taking cold showers on sickness absence, illness days and subjective well-being and to assess both the acceptability of taking cold showers as well as its effects on sickness absence and illness days as well as well-being, sleep quality, skin and hair appearance for a period of 3 months in a population of healthy and volunteering participants.
Read the detailed description
The beneficial potential of cold-water immersion has been recognized throughout human history, with early references dating back to 1600 before Christ. These beneficial effects of the external application of cold water are also seen in more recent and more systematic approaches. Notably, cold water immersion had significant and positive effects on metabolic and catabolic processes, neurotransmitters and hormones, immune parameters as well as on more global markers of health, such as sick leave and quality of life. Also, cold showers have been proposed to be of use in the treatment of depression and there are anecdotal and uncontrolled reports as well as news coverage on taking cold showers - usually in contrast to warm or hot water - showing positive effects for skin and hair. For example, cold water tightens and constricts the blood flow which gives the skin and hair a healthier glow and decreases transepidermal water loss contributing to better skin hydration, while hot showers can lead to dried out skin. Noteworthy, none of these studies reported negative events related to cold water treatment as well as no negative long-term effects.
Furthermore, a recent study on 3018 healthy participants without any experience of cold showering and which were randomized to a (hot to-) cold shower for 30, 60, 90 seconds or normal (warm) showers for 30 days followed by 60 days of showering cold at their own discretion for the intervention groups - reported that 79% of participants taking cold showers completed the intervention protocol and that taking (hot to-) cold showers reduced sickness absence by 29% in comparison to participants taking normal hot showers (incident rate ratio: 0.71, P = 0.003). Importantly, no related serious adverse events were reported.
Next to these beneficial effects on health and well-being, taking cold showers has a rather neglected, but none the less important effect as taking cold showers substantially reduces individual CO2 emission. On the basis of the CO2 emission of the average electricity mix used in Switzerland (kwH=169g CO2) and the average habit of taking warm showers (Switzerland: 8.7 minutes 6 times per week, with 15 litres/minute of warm water of 35°C), taking warm water showers produces up to 248 kg of CO2 per person and year, which corresponds to a flight from Zurich to Paris and back. This CO2 emission per year significantly increases when the house-hold is run on natural gas (296 kg) or oil (390 kg). By ratifying the Paris Convention, Switzerland has committed itself to reducing greenhouse gas emissions by 50% by 2030 compared with 1990 levels. With the previously calculated example, 15% of per capita CO2 emissions could be saved to meet the 2030 target (25% if the house runs on oil; 19% on natural gas). Considering the urgent need to cut down CO2 emission, this neglected potential could be used to substantially reduce individual CO2 emission, besides achieving beneficial health and well-being effects.
Considering the beneficial individual and environmental effects, investigators set out to replicate the recent study on the effects of taking cold showers on sickness absence, illness days and subjective well-being and to assess both the acceptability of taking cold showers as well as its effects on sickness absence and illness days as well as well-being, sleep quality, skin and hair appearance for a period of 3 months in a population of healthy and volunteering participants.
- Conditions
- Sick Leave
- Being tested
- Taking cold showers
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Taking cold showersBehavioural
Showering behaviour
| Study group | Role | What they receive |
|---|---|---|
| Warm showers | No intervention | Participants in the warm showers condition are instructed to continue their normal warm showers throughout the study |
| Cold showers | Experimental | Participants in the cold showers condition will be asked to take cold showers over a time period of 3 months Receives: Behavioral: Taking cold showers |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change of sickness absence
Sickness absence will be assessed at baseline and then monthly for 3 months. Participants are asked to retrospectively indicate the total number of days of absence from their work due to sickness. If participants indicate sickness absence over five days, they are asked for the reason.
Measured: Assessed at baseline and then monthly for 3 months
Change in number of illness days
Illness days will be assessed at baseline and then monthly for 3 months. Participants are asked to retrospectively indicate the number of days that they have had symptoms of illness, cold or flu during the last month. If participants indicate illness over five days, they are asked for the reason.
Measured: Assessed at baseline and then monthly for 3 months
Secondary outcomes (9)
World Health Organization (WHO) Five Well-Being Index
The World Health Organization (WHO) Five Well-Being Index is a short questionnaire designed to measure well-being. The World Health Organization (WHO) Five Well-Being Index consists of five questions. The answers are given on a six-level scale (0 - 5, where 0 represents "No time at all" and 5 "All the time"). The raw value is obtained by adding the answers. The raw value ranges from 0 to 25, where 0 is the lowest quality of life and 25 is the highest quality of life. The percentage value of 0 -100 is obtained by multiplying by 4. The percentage value 0 denotes the worst state of health, 100 the best. The processing time is less than one minute. Example: In the last 4 weeks I was happy and in a good mood.
Measured: Assessed at baseline and then monthly for 3 months
Questionnaire for positive aspects of well-being in adults
The Questionnaire for positive aspects of well-being in adults is a psychological self-evaluation procedure for the assessment of positive aspects of well-being in adults. The Questionnaire for positive aspects of well-being in adults consists of 16 questions, of which 4 questions each are assigned to one of the following four scales: Ability to work under pressure, vitality, enjoyment, inner peace. The answers are given on a 6-level scale (1 - 6, where 6 represents "Does not apply at all" and 1 "Is absolutely true"). The processing time is estimated at five to ten minutes by adding up the 16 items you get an overall result between 16 - 96, whereas a lower overall result shows a higher physical wellbeing. Example: There's hardly anything that can upset me.
Measured: Assessed at baseline and then monthly for 3 months
International Physical Activity Questionnaire
The International Physical Activity Questionnaire is a short questionnaire designed to measure physical activity. The International Physical Activity Questionnaire consists of six questions, of which 3 questions each are assigned to one of the following two scales: Strong physical exertion and light physical exertion. Either you have to tick an answer or you will be asked for a time in hours and minutes per week. The processing time is estimated at three minutes. Example: If you are thinking about physical activities where you are at least a little out of breath, such as running, hiking, dancing, gardening or many sports, how many days a week do you do physical activities of this kind?
Measured: Assessed at baseline and then monthly for 3 months
Pittsburgh Sleep Quality Index
The Pittsburgh Sleep Quality Index is a self-report questionnaire that assesses sleep quality over a 1-month time interval. The measure consists of 19 individual items, creating 7 components that produce one global score, and takes 5-10 minutes to complete. The questionnaire offers seven component scores and one composite score. The component scores consist of subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Each item is weighted on a 0-3 interval scale. The global Pittsburgh Sleep Quality Index score is then calculated by totalling the seven component scores, providing an overall score ranging from 0 to 21, where lower scores denote a healthier sleep quality. Example: How tired are you during the day?
Measured: Assessed at baseline and then monthly for 3 months
Skin quality questionnaire
The Skin quality questionnaire is a short self-report questionnaire that assesses hand and skin quality. The measure consists of 4 items, whereas they measure appearance, intactness, moisture con-tent and sensation on a 7-level scale, where higher scores denote a healthier quality of skin. The processing time is less than one minute each. Example: Appearance: Abnormal: redness, stains, rash. Normal: no redness, stains or rashes
Measured: Assessed at baseline and then monthly for 3 months
Showering behaviour concerning frequency
At baseline, habitual showering behaviour will be assessed online and participants will rate their habitual showering behaviour in terms of frequency, duration, equipment (i.e. kind of shower head) and temperature. Participants are also asked to measure and indicate the temperature of their showers with a thermometer, but this is not obligatory for study continuation. After randomization, participants are asked to complete weekly online assessments of the showering behaviour for the duration of the study, i.e. frequency, duration, equipment (i.e. kind of shower head) and temperature. The intervention group is asked to shower for 3 months at the coldest level only, i.e. with water at the coldest level. The temperature of cold water will be estimated on the basis of average temperatures for the specific geographical region (which are obtained from local waterworks) and the dates of participation
Measured: Assessed at baseline and then weekly for 3 months
Showering behaviour concerning duration
At baseline, habitual showering behaviour will be assessed online and participants will rate their habitual showering behaviour in terms of frequency, duration, equipment (i.e. kind of shower head) and temperature. Participants are also asked to measure and indicate the temperature of their showers with a thermometer, but this is not obligatory for study continuation. After randomization, participants are asked to complete weekly online assessments of the showering behaviour for the duration of the study, i.e. frequency, duration, equipment (i.e. kind of shower head) and temperature. The intervention group is asked to shower for 3 months at the coldest level only, i.e. with water at the coldest level. The temperature of cold water will be estimated on the basis of average temperatures for the specific geographical region (which are obtained from local waterworks) and the dates of participation
Measured: Assessed at baseline and then weekly for 3 months
Showering behaviour concerning equipment
At baseline, habitual showering behaviour will be assessed online and participants will rate their habitual showering behaviour in terms of frequency, duration, equipment (i.e. kind of shower head) and temperature. Participants are also asked to measure and indicate the temperature of their showers with a thermometer, but this is not obligatory for study continuation. After randomization, participants are asked to complete weekly online assessments of the showering behaviour for the duration of the study, i.e. frequency, duration, equipment (i.e. kind of shower head) and temperature. The intervention group is asked to shower for 3 months at the coldest level only, i.e. with water at the coldest level. The temperature of cold water will be estimated on the basis of average temperatures for the specific geographical region (which are obtained from local waterworks) and the dates of participation
Measured: Assessed at baseline and then weekly for 3 months
Showering behaviour concerning temperature
At baseline, habitual showering behaviour will be assessed online and participants will rate their habitual showering behaviour in terms of frequency, duration, equipment (i.e. kind of shower head) and temperature. Participants are also asked to measure and indicate the temperature of their showers with a thermometer, but this is not obligatory for study continuation. After randomization, participants are asked to complete weekly online assessments of the showering behaviour for the duration of the study, i.e. frequency, duration, equipment (i.e. kind of shower head) and temperature. The intervention group is asked to shower for 3 months at the coldest level only, i.e. with water at the coldest level. The temperature of cold water will be estimated on the basis of average temperatures for the specific geographical region (which are obtained from local waterworks) and the dates of participation
Measured: Assessed at baseline and then weekly for 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Oct 2019
- Study start26 Oct 2021
- Primary completion17 Mar 2023
- Study completion31 Dec 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sick LeaveStudies of the same condition, open and under way.
- More trials run by University Hospital, Basel, SwitzerlandThe 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 350 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Basel, Switzerland
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Jens Gaab, Prof. Dr., Principal investigator, Faculty for Psychology at the University of Basel
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04130126
- Sponsor's protocol ID
- eknz2019-00529
- Status last verified
- May 2024
- First submitted
- 24 Sep 2019
- Last updated
- 8 May 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 May 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Feasibility and Effects of Taking Cold Showers: A Randomized Controlled Study
- ClinicalTrials.gov ID
- NCT04130126
- Acronym / sponsor ID
- eknz2019-00529
- Conditions
- Sick Leave
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 350 participants (actual)
- Lead sponsor
- University Hospital, Basel, SwitzerlandUniversity, hospital or other
- Study start
- 26 Oct 2021 (actual)
- Primary completion
- 17 Mar 2023 (actual)
- Study completion
- 31 Dec 2023 (actual)
- First posted
- 17 Oct 2019 (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.
Considering the beneficial individual and environmental effects, investigators set out to replicate the recent study on the effects of taking cold showers on sickness absence, illness days and subjective well-being and to assess both the acceptability of taking cold showers as well as its effects on sickness absence and illness days as well as well-being, sleep quality, skin and hair appearance for a period of 3 months in a population of healthy and volunteering participants.
Detailed description
The beneficial potential of cold-water immersion has been recognized throughout human history, with early references dating back to 1600 before Christ. These beneficial effects of the external application of cold water are also seen in more recent and more systematic approaches. Notably, cold water immersion had significant and positive effects on metabolic and catabolic processes, neurotransmitters and hormones, immune parameters as well as on more global markers of health, such as sick leave and quality of life. Also, cold showers have been proposed to be of use in the treatment of depression and there are anecdotal and uncontrolled reports as well as news coverage on taking cold showers - usually in contrast to warm or hot water - showing positive effects for skin and hair. For example, cold water tightens and constricts the blood flow which gives the skin and hair a healthier glow and decreases transepidermal water loss contributing to better skin hydration, while hot showers can lead to dried out skin. Noteworthy, none of these studies reported negative events related to cold water treatment as well as no negative long-term effects.
Furthermore, a recent study on 3018 healthy participants without any experience of cold showering and which were randomized to a (hot to-) cold shower for 30, 60, 90 seconds or normal (warm) showers for 30 days followed by 60 days of showering cold at their own discretion for the intervention groups - reported that 79% of participants taking cold showers completed the intervention protocol and that taking (hot to-) cold showers reduced sickness absence by 29% in comparison to participants taking normal hot showers (incident rate ratio: 0.71, P = 0.003). Importantly, no related serious adverse events were reported.
Next to these beneficial effects on health and well-being, taking cold showers has a rather neglected, but none the less important effect as taking cold showers substantially reduces individual CO2 emission. On the basis of the CO2 emission of the average electricity mix used in Switzerland (kwH=169g CO2) and the average habit of taking warm showers (Switzerland: 8.7 minutes 6 times per week, with 15 litres/minute of warm water of 35°C), taking warm water showers produces up to 248 kg of CO2 per person and year, which corresponds to a flight from Zurich to Paris and back. This CO2 emission per year significantly increases when the house-hold is run on natural gas (296 kg) or oil (390 kg). By ratifying the Paris Convention, Switzerland has committed itself to reducing greenhouse gas emissions by 50% by 2030 compared with 1990 levels. With the previously calculated example, 15% of per capita CO2 emissions could be saved to meet the 2030 target (25% if the house runs on oil; 19% on natural gas). Considering the urgent need to cut down CO2 emission, this neglected potential could be used to substantially reduce individual CO2 emission, besides achieving beneficial health and well-being effects.
Considering the beneficial individual and environmental effects, investigators set out to replicate the recent study on the effects of taking cold showers on sickness absence, illness days and subjective well-being and to assess both the acceptability of taking cold showers as well as its effects on sickness absence and illness days as well as well-being, sleep quality, skin and hair appearance for a period of 3 months in a population of healthy and volunteering participants.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Warm showers | No intervention | –Participants in the warm showers condition are instructed to continue their normal warm showers throughout the study |
| Cold showers | Experimental | Behavioral: Taking cold showersParticipants in the cold showers condition will be asked to take cold showers over a time period of 3 months |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- healthy participants between 18 and 65 years of age
- no cold shower taken on a regular basis by participants
Key exclusion criteria (2 listed)
- pregnant or lactating women
- subjects with cardiac, pulmonary or any other severe disease by self-report.
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 |
|---|---|---|
| Taking cold showersShowering behaviour | Behavioural | Cold showers |
Primary outcome
Change of sickness absence
Time frame: Assessed at baseline and then monthly for 3 months
Sickness absence will be assessed at baseline and then monthly for 3 months. Participants are asked to retrospectively indicate the total number of days of absence from their work due to sickness. If participants indicate sickness absence over five days, they are asked for the reason.
Change in number of illness days
Time frame: Assessed at baseline and then monthly for 3 months
Illness days will be assessed at baseline and then monthly for 3 months. Participants are asked to retrospectively indicate the number of days that they have had symptoms of illness, cold or flu during the last month. If participants indicate illness over five days, they are asked for the reason.
9 secondary outcomes
World Health Organization (WHO) Five Well-Being Index
Time frame: Assessed at baseline and then monthly for 3 months
Questionnaire for positive aspects of well-being in adults
Time frame: Assessed at baseline and then monthly for 3 months
International Physical Activity Questionnaire
Time frame: Assessed at baseline and then monthly for 3 months
Pittsburgh Sleep Quality Index
Time frame: Assessed at baseline and then monthly for 3 months
Skin quality questionnaire
Time frame: Assessed at baseline and then monthly for 3 months
Showering behaviour concerning frequency
Time frame: Assessed at baseline and then weekly for 3 months
Showering behaviour concerning duration
Time frame: Assessed at baseline and then weekly for 3 months
Showering behaviour concerning equipment
Time frame: Assessed at baseline and then weekly for 3 months
Showering behaviour concerning temperature
Time frame: Assessed at baseline and then weekly for 3 months
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 8 May 2024.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Jens Gaab, Prof. Dr. principal investigator
Faculty for Psychology at the University of Basel
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Taking cold showers in people with Sick Leave, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.
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 2 inclusion and 2 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 8 May 2024. 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 Switzerland. 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?
Change of sickness absence (time frame: Assessed at baseline and then monthly for 3 months). The study lists 2 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 8 May 2024.