Cognitive Performance During Night Work in the Cold

Area of Science:

• Environmental Physiology
• Occupational Health
• Cognitive Science

Background:

• Night work is common in many industries, posing potential risks to worker health and performance.
• Low ambient temperatures can exacerbate the challenges associated with night work, potentially affecting physiological and cognitive functions.

Purpose of the Study:

• To investigate the impact of night work at low ambient temperatures on cognitive performance, physiological responses, and subjective well-being.
• To test the hypothesis that cognitive performance decreases at night and is further impaired by cold exposure.

Main Methods:

• Eleven male subjects participated in controlled experiments in a climatic chamber.
• Tests were conducted during night and day at -2°C and 23°C, lasting 6 hours each.
• Measurements included cognitive tests (short-term memory, reaction time), core and skin temperature, thermal comfort, sleepiness, and cortisol levels.

Main Results:

• Lower mean skin temperature and thermal sensation were recorded at -2°C compared to 23°C.
• Night work led to increased sleepiness and lower cortisol levels, independent of ambient temperature or thermal comfort.
• Cognitive performance (short-term memory and reaction time) remained unaffected by night work or ambient temperature variations.

Conclusions:

• While low ambient temperatures reduce skin and core temperature at night, they do not impair cognitive performance (short-term memory, reaction time) if adequate protective clothing is used.
• Night work increases sleepiness and decreases cortisol levels compared to daytime work, irrespective of cold exposure.
• The findings suggest that cognitive functions crucial for tasks like reaction time and memory are resilient to night work in cold environments with appropriate thermal protection.