No matter how harmonious your workplace might be, what temperature to set the thermostat seems to be the one thing that no one can ever agree on.
Luckily, scientists have now revealed the ideal temperature to keep everyone happy – and it might be a little warmer than some people expect.
According to research conducted by home heating experts BOXT, Britons feel happiest, calmest, and most productive at a balmy 21°C (70°F).
Scientists call this the ideal ‘ThermoState’, and say it could be key to maximising your mood and alertness.
Too far outside the range of 19.5°C to 20.6°C (67.1-69.1°F), and you might find that your emotional and physical well-being start to drop off.
Clinical psychologist and mental health expert Dr Sophie Mort says: ‘The ThermoState is like emotional central heating, the point where the brain and body work in sync.
‘Temperature regulation isn’t just about physical comfort, it is closely tied to psychological wellbeing, influencing memory, emotional processing, stress response and how relaxed or tense we feel in our everyday environments.
‘Even relatively small shifts in indoor warmth can affect mood, energy, sleep quality and motivation, particularly during winter when emotional resilience is already under pressure.’
Scientists have revealed that the optimal temperature for the office thermostat is 21°C (70°F) (stock image)
In a new study, BOXT surveyed 2,000 British adults about their temperature preferences.
This revealed that our temperature responses follow a shallow ‘mood-heat curve’, with comfort and performance peaking in a narrow ideal range.
If the environment is either too hot or too cold, working ability and happiness start to fall surprisingly fast.
‘There is a very real physiological response to temperature,’ says Professor Mort.
‘Being too hot or too cold can quietly undermine our state of mind in ways we often underestimate.’
When the temperature fell below 17°C (62.6°F), the researchers found that mood and alertness started to decline.
By the time temperatures hit just 16.7°C (62.1°F), people start to lose focus and experience poorer sleep.
In 2021, a study found that volunteers exposed to colder temperatures experienced ‘significantly disturbed’ cognitive responses.
Researchers found that Britons’ temperature preferences follow a shallow curve, with a small ideal region between 19.5°C and 20.6°C (67.1-69.1°F) where mood and productivity are highest
Blood pressure, heart rate, and respiration rate all increased as the temperature fell, indicating that the body’s stress response was activated.
Dr Mort says: ‘When indoor temperatures fall too low, the body naturally shifts into heat-conserving mode.
‘This can increase stress hormones, subtly reduce cognitive performance and make emotional regulation and sustained concentration more difficult, which is why many people in colder environments describe feeling more tense, distracted or irritable.’
However, that doesn’t mean the solution is to crank the heat up when you start to feel grouchy.
‘Once we push beyond this ThermoState zone into overheating, reaction time and mental sharpness begin to decline, and fatigue or restlessness can set in,’ says Dr Mort.
When temperatures begin to exceed 21.6°C (70.9°F), mood and alertness begin to decline once again.
At 22°C (71.6°F), people report becoming more irritable and combative.
Any hotter than that, and feelings of fatigue or sluggishness start to emerge.
There are some regional variations in the ideal ‘ThermoState’, with people in Brighton and Glasgow both preferring temperatures up to 1.2°C (2.16°F) hotter than the national average
This supports previous studies, which have found that overly warm environments can impair reaction times and drain cognitive energy.
Research has shown that indoor temperatures above 24°C (75.2°F) impair cognitive performance, particularly in terms of processing speed.
While complex reasoning tasks are slightly more resilient, there is still a general decline in mental performance when the temperature is too high.
That means turning up the heat in the office might be the reason you feel sleepy and frustrated with your colleagues.
However, it is also important to remember that your exact ideal ThermoState might be slightly different to those of your co-workers.
While most people work best at temperatures around 21°C (70°F), there is some variation to either side.
BOXT’s survey found that people in Brighton and Glasgow typically prefer temperatures up to 1.2°C (2.16°F) hotter than the national average.
Meanwhile, people in Plymouth prefer a chillier environment with the temperature set 1°C (1.8°F) cooler than the average.
