If you work outside, it’s important to know about cold stress. Cold stress is a preventable danger that involves a person’s skin temperature – and eventually internal body temperature – dropping to levels at which the body cannot warm itself, according to OSHA. This can lead to serious injuries, including permanent tissue damage and death. Types of cold stress include trench foot, frostbite and hypothermia.

Trench foot happens when a worker’s foot is exposed to prolonged wet and cold conditions.

Frostbite occurs when a person’s skin and tissue become frozen, and can lead to severe damage and amputation. “The risk of frostbite is increased in people with reduced blood circulation and among people who are not dressed properly for extremely cold temperatures,” OSHA states.

Hypothermia happens when body temperature drops below 95° F and the body cannot produce heat fast enough to counteract the lost heat. This condition can be deadly.

From the "First Aid" course offered by the National Safety Council. Learn more about NSC first aid and CPR training – including online and classroom training for learners, and courses and materials for instructors. © 2015 National Safety Council

How to prevent cold stress

Employers should know what the wind chill factor is so they can determine whether working outside is safe.

“It is also important to monitor workers’ physical condition during tasks, especially new workers who may not be used to working in the cold, or workers returning after spending some time away from work,” OSHA notes.

To help prevent cold stress, employers should instruct workers to:

• Properly dress for cold and wet conditions.
• Recognize cold stress symptoms, including reddened skin, pain, numbness and blisters.
• Know when to seek medical help.

Employers also should schedule frequent breaks in warm places and ensure employees who are outside in the cold work in pairs. For more on preventing cold stress, as well as information on determining wind chill levels, go to OSHA.gov's winter weather page.