Cold stress: types and how to avoid injury
Cold stress happens when the body loses heat faster than it can make it. It can occur in a freezer or on a mild, wet, windy day. NIOSH names four main cold-related illnesses: hypothermia, frostbite, trench foot and chilblains.
The four types
Hypothermia
Body temperature falls below normal. Early signs include shivering, tiredness, confusion and clumsiness. It is an emergency. Call 911, move the person somewhere warm, replace wet clothing with dry, and warm the center of the body first.
Frostbite
Freezing of the skin and the tissue under it, most often in fingers, toes, ears and nose. Skin may look pale, waxy or hard and feel numb. Get medical care, and do not rub the area.
Trench foot
Damage from long exposure to wet and cold, even above freezing. Feet may feel cold, numb, swollen or tingly. Keep feet dry and change wet socks promptly.
Chilblains
Painful, inflamed skin from repeated exposure to cold, usually on the hands and feet. It can look red, swollen and itchy.
Symptoms vary. When in doubt, treat it as an emergency.
Who is at risk
NIOSH lists outdoor workers, people in poorly insulated or unheated areas, people without shelter, and workers in regions unaccustomed to winter, where near-freezing temperatures can still cause cold stress. Wet clothing, wind and fatigue add to the risk. A cool, wet, windy day in the South can still cause cold stress.
What employers can do
Schedule cold jobs for warmer months or the warmer part of the day. Use relief workers or add people for long jobs. Provide warm liquids and warm areas for breaks, limit time outside on extremely cold days and monitor workers who are at higher risk. Train everyone on the risks, prevention, symptoms, how to watch themselves and coworkers, treatment and protective equipment.
What workers can do
Wear several layers of loose clothing, and protect the ears, face, hands and feet, with waterproof insulated boots and a hat. Take breaks in warm places. Carry extra socks, gloves, a hat, a jacket and blankets, and keep a thermometer and chemical hot packs in the first aid kit. Avoid touching cold metal with bare skin, and watch yourself and your coworkers for symptoms.
Cold and musculoskeletal injury
Cold stiffens muscles and reduces dexterity and grip, which raises the risk of slips, strains and dropped loads. Warm up before heavy work, slow down on wet or icy surfaces and report pain early.
Keep a thermometer and chemical hot packs in the workplace first aid kit. The broader checklist is in our guide to office emergency equipment. Plain water is enough for hydration in any weather, as the evidence on alkaline water shows. Cold also stiffens muscles, which links to our guidance on injury prevention at work. See our other workplace health guides for seasonal and everyday hazards.
This page is general information. It is not medical or legal advice and does not replace the rules that apply to your workplace.
References
About the clinical team behind this page
Dr. Pelham Williams IV is Regional Medical Director for Nova’s Southeast region, based in Atlanta. His practice centers on the evaluation and non-operative management of musculoskeletal and work-related injuries, including acute joint injuries and repetitive-strain problems, and he reviews content on occupational injury and sports injury diagnosis.
Dr. Arnaldo Manuel Mora is Medical Director and leads clinical governance at Nova. His background is in internal and occupational medicine. He oversees diagnostic intake, baseline laboratory review and the safety standards that apply before any prescription therapy, including pharmacy sourcing and contraindication screening as described in our safety guide.
Medical disclaimer: The information on this site is for education and does not replace a consultation, diagnosis or treatment. Full credentials are on our physicians and clinical governance page.
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Individual results vary and no outcome is guaranteed. This page is general information, not medical advice.