Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Exposure to cold air is associated with increased morbidity (disease) and mortality (death) in the
general population. Exposure to extreme cold weather can cause shivering, tiredness, changes in breathing. It can lead to hypothermia (which means their body temperature drops to dangerously low levels) and hypoventilation (slow breathing). It is difficult to study effects of whole-body exposure to cold air under controlled conditions in real life due to safety issues. The aim of this study is to develop a controlled setup to allow investigation of human airway responses of exposures to subfreezing temperatures and compare the impact of the weather on participants with different respiratory issues.

Who can participate?
Adults aged 18 and older who are either healthy, have allergies, are asthmatic, have COPD or are elite skiers.

What does the study involve?
Participants undergo an exercise test to predict their maximum rate that they use oxygen during exercise. Participants are randomly allocated to be exposed to the either 0 °C, -10 °C and -20 °C over three separate sessions at least one week apart. Each exposure session consists of alternating 15 minute periods of upright resting and walking for one hour on a treadmill at a speed that is predicted to cause participants to use 50% of their maximum oxygen levels. General and airway symptoms are recorded using participant interviews during the exposures sessions.

What are the possible benefits and risks of participating?
There are no direct benefits with participating. There is a risk of developing common temporary symptoms associated with exposure to cold air such as rhinorrea (runny or stuffed nose), dyspnea (difficulty breathing), cough, and a general feeling of cold.

Where is the study run from?
Östersund Hospital (Sweden)

When is the study starting and how long is it expected to run for?
January 2015 to December 2018

Who is funding the study?
1. Gunhild och Assar Karlssons Donations Fund (Sweden)
2. Region Jämtland Härjedalen (Sweden)

Who is the main contact?
Dr Nikolai Stenfors

Trial website

Contact information



Primary contact

Dr Nikolai Stenfors


Contact details

Östersund Hospital
Kyrkgatan 16
+46 70 6092778

Additional identifiers

EudraCT number number

Protocol/serial number

Version 3

Study information

Scientific title

A qualitative study of airways symptoms of experimental exposure to cold air


Study hypothesis

1. Experimental exposure to cold air induces airway symptoms
2. The airway symptoms are correlated to exposure temperature
3. Visavi symptoms, healthy subjects differ from subjects with allergic rhinitis and/or obstructive lung disease

Ethics approval

Regional Ethical Review Board Umeå University, 2015-10-06, ref: dnr 2015/245-31

Study design

Randomised double-blind cross over trial

Primary study design


Secondary study design

Randomised cross over trial

Trial setting


Trial type


Patient information sheet

See additional files (in Swedish)


Allergic rhinitis, asthma, COPD


Participants undergo a ramped maximum exercise test on a motorised treadmill to predict their maximum oxygen consumption (VO2max). Participants are allocated to one of five groups based on their diagnoses or their specifications.

1. Healthy group
2. Allergic rhinitis group
3. Asthma group
4. COPD group
5. Elite Skier group

Participants in each of the groups are randomly exposed to either a 0 °C, -10 °C and -20 °C environmental chamber over three separate occasions at least one week apart. Each exposure session consists of alternating 15 minute periods of upright resting and walking for one hour on a treadmill at a speed that is predicted to elicit 50% of the participants VO2max.

Participants are monitored for their general and airway symptoms through participant interviews during each of the exposures.

Intervention type



Drug names

Primary outcome measure

General and airways symptoms are recorded by focused open interviews (symptom intensity is measured using the Borg CR10 scale) at session one, two and three.

Secondary outcome measures

Group comparison of airway symptoms are measured using focused open interviews using the Borg CR10 scale at session one, two and three.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Healthy group:
1. Non-smokers
2. No allergy or respiratory disease
3. Not on medication
4. Aged 18 and older

Allergic rhinitis group:
1. Non-smokers
2. Symptoms of allergy to common airborne allergens
3. Positive skin prick test
4. Aged 18 and older

Asthma group:
1. Non-smoker
2. Physician-diagnosed asthma (stable)
3. Regular use of asthma medications in the past three months
4. Aged 18 and older

COPD group:
1. Physician diagnosed COPD
2. Current or former smoker (at least ten pack years)
3. FEV1/FVC <0.7 and FEVI <80% of predicted post bronchodilation
4. Daily use of COPD pharmacotherapy for the last three months
5. Aged 18 and older

Elite Skier group:
1. Competitive skiers
2. >400 training hours/year
3. No allergy or asthma
4. Aged 18 and older
5. Non-smokers

Participant type


Age group




Target number of participants

8-20 in each group

Participant exclusion criteria

Recent airway infection

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Östersund Hospital
Kyrkgatan 16

Sponsor information


Umeå University

Sponsor details

901 87

Sponsor type




Funder type


Funder name

Gunhild och Assar Karlssons Donations Fund

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Region Jämtland Härjedalen

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer reviewed journal.

IPD sharing plan:
The datasets generated during and/or analysed during the current study are not expected to be made available due to a requirement in the ethical approval there is statement that the data would not be shared to unauthorised persons. The dataset will be held at a server at Umeå University.

Intention to publish date


Participant level data

Not expected to be available

Basic results (scientific)

Publication list

2019 results in: [added 08/04/2019]

Publication citations

Additional files

Editorial Notes

08/04/2019: Publication reference added. 07/11/2018: The following changes were made: 1. The recruitment end date was changed from 01/10/2018 to 28/02/2018. 2. The overall trial end date was changed from 31/12/2018 to 01/05/2018. 3. The intention to publish date was changed from 01/09/2018 to 01/10/2018. 14/11/2017: The intention to publish date has been updated from 01/05/2017 to 01/09/2018.