From the Guidelines
Cold temperatures are more likely to increase alertness, as they stimulate the body's natural response to maintain homeostasis, increasing the production of norepinephrine and improving blood circulation to the brain. This is supported by the concept of a U-shaped curve describing the effect of thermal environment on cognitive performance, where temperatures that are too cool or too warm can cause discomfort and decrease work performance and well-being 1. The optimal temperature range for cognitive performance is between 18-24 °C, as recommended by the WHO 1.
When considering the impact of temperature on alertness, it's essential to note that individual tolerance to temperature variations plays a significant role. However, in general, colder temperatures tend to increase alertness by stimulating the body's natural response to cold stress. In contrast, warmer temperatures can lead to relaxation and decreased alertness. The study of indoor air quality guidelines highlights the importance of thermal comfort in maintaining cognitive performance and overall well-being 1.
Key points to consider:
- The thermal environment has a significant impact on cognitive performance, with a U-shaped curve describing the relationship between temperature and performance 1.
- Temperatures between 18-24 °C are considered optimal for cognitive performance, as recommended by the WHO 1.
- Cold temperatures stimulate the production of norepinephrine, a hormone and neurotransmitter that promotes alertness and attention.
- Brief exposure to cold temperatures can be an effective way to increase alertness, such as taking a cool shower or stepping outside in winter.
From the Research
Temperature and Alertness
- The relationship between temperature and alertness is complex, and research suggests that both high and low temperatures can have an impact on an individual's alertness and mental health 2.
- Higher temperatures have been shown to increase emergency department visits for mental illness, suicides, and self-reported days of poor mental health, while cold temperatures reduce negative mental health outcomes 2.
- In terms of sleep duration, research suggests that colder temperatures do not significantly influence sleep duration, while higher temperatures can lead to a decline in sleep duration 3.
- The effect of temperature on sleep duration can be significant, with hot days (>25 °C) resulting in a sleep loss of -13.3 minutes, and this effect can be even stronger if preceded by several hot days 3.
Factors Influencing Temperature Perception
- Several factors can influence an individual's perception of temperature-related health risks, including knowledge of the relationship between temperature and health risks, presence of comorbidities, age and self-identity, and past experience with weather 4.
- These factors can affect an individual's ability to perceive and respond to temperature-related health risks, and can be important considerations for public health risk communication and behavior change interventions 4.
Mechanisms Underlying Temperature Effects
- The mechanisms underlying the effects of temperature on alertness and mental health are not fully understood, but may involve disruptions to sleep patterns and other physiological processes 2, 3.
- Further research is needed to fully understand the relationships between temperature, alertness, and mental health, and to develop effective strategies for mitigating the negative effects of temperature extremes on human health 2, 3.