The range of thermal comfort that is neutrally acceptable without health impact has been proposed as running between 17°C as the lowest and 31°C as the highest acceptable temperature. (Weihe 1987, World Health Organization 1990).

• use a thermal mannequin
• measure skin temperature and the power needed to maintain temperature
• calculate the mean thermal at 25 body locations

See presentation on thermal comfort measurements here.

If the air temperature is maintained at 27 °C in the kitchen, employee productivity falls to 80 %. See the table of productivity loss in warm working areas: productivity / temperature. 

Labour shortages are the greatest challenge that commercial restaurants face today. The average age of a restaurant worker is between 16 and 24 years. In a recent survey conducted by the National Restaurant Association in the USA, more than 52 % of respondents said that finding qualified motivated labour was their main concern.

In a restaurant with an annual turnover of EUR 1,500,000:

• Typical profit could be EUR 75,000 (5%)
• Salary costs could be at the level of EUR 250,000
• Productivity loss of 30% (the room's temperature is 6 °C above the thermally neutral level) means EUR 75,000 in annual losses in the workers' productivity
• In addition, an improved working environment decreases absenteeism and employee turnover, also reducing recruitment fees.