Effects of cold on health and safety
- General cooling and hypothermia. A drop in core temperature with shivering, confusion, loss of coordination, and, below 35 degrees, hypothermia, which can be fatal.
- Local cooling and frostbite. Loss of sensation and dexterity in hands and feet, chilblains, immersion foot, and superficial and deep frostbite on extremities, nose, and ears, exacerbated by wind and humidity.
- Cooling of the respiratory tract. Irritation and bronchoconstriction from inhalation of very cold air, especially with intense activity.
- Effects on performance and safety. Reduction in manual dexterity, strength, attention and reaction time, with an increase in errors and accidents.
- Worsening of pathologies. Cardiovascular, respiratory, circulatory (Raynaud’s syndrome) and musculoskeletal diseases, and increased sensitivity in certain people, medications and alcohol consumption.
- Aggravating factors: Wind, humidity, contact with cold metals and liquids, wet clothing, inactivity, fatigue, and prolonged exposure.
Applicable regulatory framework
Royal Decree 486/1997 establishes that exposure to the environmental conditions of workplaces must not pose a risk to safety and health, sets temperatures between 17 and 27 degrees for sedentary work in enclosed premises and between 14 and 25 degrees for light work, and requires that in outdoor workplaces and in premises that cannot be enclosed, measures be taken to protect people from inclement weather; when working conditions, such as in cold storage rooms, require temperatures outside these ranges, protection is ensured through organizational measures and protective equipment.
Royal Decree 1561/1995 on special working hours regulates, in Article 31, work in cold storage and freezing chambers: between 0 and -5 degrees Celsius, the normal working day is maintained with a ten-minute recovery break every three hours of uninterrupted work inside; between -5 and -18 degrees Celsius, the maximum stay is six hours with fifteen-minute breaks for every hour of uninterrupted work; and below -18 degrees Celsius, the maximum stay is six hours with fifteen-minute breaks for every forty-five minutes, with the workday potentially being completed with work outside the chambers. Royal Decree 773/1997 governs the selection and use of clothing and equipment for protection against the cold, and INSST Technical Prevention Notes 1036 and 1037 detail the assessment and preventive measures.
Assessment and preventive measures
- Evaluation. IREQ method of the UNE-EN ISO 11079 standard to determine the necessary clothing insulation and maximum exposure time, wind cooling index for the outside and evaluation of local cooling by contact and convection.
- Technical measures. Protection against wind and humidity, localized heating in fixed stations, insulation of metal surfaces, handles and tools, and heated rest areas.
- Organizational measures. Limiting exposure times, recovery breaks in warm places, task rotation, acclimatization, working in pairs in severe conditions, adjusting the activity and providing hot drinks.
- Protective clothing and equipment. Layered cold-weather protective clothing, appropriate for the required insulation, insulating and non-slip gloves and footwear, head and face protection, and replacement of wet clothing.
- Information and training. Recognition of the signs of hypothermia and frostbite, use of clothing, hydration and nutrition habits, and emergency response.
- Health surveillance. Identification of particularly vulnerable individuals and monitoring of health effects.
Organizational application: how to manage the cold at work
- Identify jobs and tasks with exposure to cold (chambers, outdoors in winter, altitude, cold water, contact with cold surfaces) and the people exposed, including those who are especially sensitive.
- Evaluate exposure using the IREQ method and wind and local cooling indices, determining the necessary clothing insulation and maximum exposure and recovery times.
- Apply the technical measures (protection against wind and humidity, localized heating, surface insulation) and organizational measures (times, breaks, rotation, acclimatization, working in pairs) and comply with the rest periods of Royal Decree 1561/1995 in cold storage rooms.
- Select and deliver clothing and cold protection equipment appropriate to the required insulation, with criteria for replacement and drying.
- Train and inform staff about the effects of cold, warning signs, use of clothing and emergency procedures, and have a first aid protocol in place.
- Integrate specific health monitoring and adapt the jobs of particularly sensitive people.
- Review the assessment and measures with changes in season, facilities or organization and record the incidents.
Preventive management software allows linking positions with exposure to cold to the assessment and exposure and recovery times, managing the delivery and renewal of protective clothing, planning training and health monitoring, recording incidents and maintaining traceability of compliance with rest periods in cold storage rooms.
Limits and common mistakes
- Considering the cold a nuisance without assessing the exposure or determining the required insulation of the clothing.
- Failure to respect the stay times and recovery breaks in freezing chambers.
- Providing inadequate protective clothing for the level of cold, without layers or protection for hands, feet and face, or not replacing wet clothing.
- Ignoring wind and humidity in outdoor work and not having temperate recovery areas.
- Not identifying particularly sensitive people or training them on the signs of hypothermia and frostbite.
- Forgetting the increased risk of accidents due to loss of dexterity and attention in cold environments.
The specific assessment depends on environmental conditions, activity, and clothing; this sheet is for informational purposes only.
Practical example
Situation: A logistics operator of frozen products with chambers at minus 22 degrees and open loading docks reviews cold management after several complaints of numbness in hands and a slip on the dock.
- Assessment. The prevention service evaluates the chambers and docks using the IREQ method and the wind chill index, detecting that the clothing provided does not achieve the required insulation and that the breaks of Royal Decree 1561/1995 are not applied systematically.
- Measures. Clothing is replaced with suitable cold protection equipment including insulating gloves and footwear, curtains and enclosures are installed on the docks, a heated recovery room is set up, and occupancy control is implemented with fifteen-minute breaks every forty-five minutes.
- Organization. Staff are trained on warning signs and the use of clothing, particularly sensitive individuals are identified, and rotation with tasks outside the cold-storage chambers is established.
- Follow-up. Complaints disappear, the attendance record is integrated into the management system, and the evaluation is reviewed before each winter campaign.
Regulatory and reference framework
- Law 31/1995, of November 8. Law on the Prevention of Occupational Risks.
- Royal Decree 486/1997, of April 14. Minimum health and safety requirements in the workplace; Annex III, Environmental conditions.
- Royal Decree 1561/1995, of September 21. Special working days; article 31, work in cold storage and freezing chambers.
- Royal Decree 773/1997, of May 30. Use of personal protective equipment; protective clothing against the cold.
- NTP 1036. Cold stress (I) . Effects, sectors and method of evaluating cold stress.
- NTP 1037. Cold stress (II) . Assessment and preventive measures against cold stress.
- INSST. Thermal Environment . Thematic portal on heat and cold stress.
The UNE-EN ISO 11079 standard establishes the method for determining the required insulation of clothing (IREQ) and the effects of local cooling, and is the technical reference for the cited Technical Prevention Notes.
