Circadian rhythms and light
Alertness fluctuates throughout the day. Our bodies run on an internal clock known as the circadian rhythm, which regulates when we feel alert or sleepy over a 24-hour period. This rhythm is highly sensitive to light – especially the kind we experience in the morning. When bright light reaches our eyes after waking, it sends a powerful signal to the brain that it’s time to be awake and alert. This not only helps us feel more energised but also influences key processes like hormone release and body temperature.
Modern life, however, often means we spend our mornings indoors under artificial lighting that’s much dimmer than natural daylight. As a result, our circadian rhythms can become misaligned with our daily routines, leaving us feeling groggy or unfocused. Moreover, it can be useful to realize that also room temperature impact our alertness; warmer temperatures encouraged slower reaction and feeling less alert.
By understanding and adjusting the type and timing of light we’re exposed to - particularly in the morning - we can help our bodies transition more smoothly into the day, supporting better alertness and overall wellbeing.
Harnessing light for office environments
Harnessing light effectively in office environments is vital for supporting alertness and, by extension, productivity. While many modern workplaces are designed to maximise access to natural daylight – a key factor in aligning our internal clocks and boosting energy – exposure to sufficient light levels during the day remains a challenge. Unlike daylight, artificial light is often less bright and dynamic and can be difficult to tailor to individual needs.
For employees to truly benefit, it’s important that they have some control over their lighting environment, allowing adjustments for brightness and, where possible, colour temperature. Ultimately, daylight and a view should be prioritised wherever feasible, as it provides the most effective and natural stimulus for maintaining alertness and supporting overall wellbeing throughout the working day.
Still optimizing daylight access to the building is important since it can conflict with overheating of the building and a large energy demand for cooling. Room temperature directly impacts our alertness and productivity during the day; higher temperatures reduce alertness and result in longer reaction times as compared to a cooler environment.
Shedding light on the alertness and wellbeing of shift workers
It is well known that shift work can impact our levels of overall tiredness, productivity and general wellbeing. For shift workers working in factories, hospitals, or other settings where precision and quick decision-making are critical, the right lighting environment is essential for maintaining concentration and productivity during night shifts. Having the possibility to adjust the indoor environment to their own needs is especially important during the night. Tailored lighting and temperature conditions can help to feel comfortable also during the night and remain alert.
For those who must sleep during the day, creating an ideal rest environment means ensuring the space is dark and slightly warm, helping the body wind down and recover. Ultimately, achieving the right balance of light and temperature – tailored to the demands of the task and the needs of the worker – is key to supporting both performance and wellbeing in round-the-clock operations.
Facilities Managers should prioritise light and temperature
People naturally prefer environments with abundant daylight, and it’s especially important that those working in offices are exposed to high levels of natural light throughout the day. However, as global temperatures continue to rise, overheating is becoming a critical factor that facilities and building managers must address.
The dynamic aspects of a building – such as ventilation, daylight exposure, and heat regulation – play a vital role in occupant comfort and energy efficiency. Yet, a one-size-fits-all approach rarely works. Individual control is essential, as everyone has different preferences. Occupants need the ability to adjust their environment to suit their needs.
Solutions like dynamic solar shading are ideal for managing access to natural light and regulating indoor temperatures, particularly during the hotter summer months. These systems help maintain comfort while reducing reliance on artificial cooling.
Designing buildings to allow some light penetration during winter is equally important. Achieving a balance between summer and winter conditions is a key consideration in modern building design. This is particularly evident in countries like the Netherlands, where there is increasing focus on summer performance in architectural planning. Buildings should be more dynamic – incorporating insulation, responsive solar shading, and advanced façade engineering – to adapt effectively to seasonal changes.
