Colloquially, room temperature is the range of air temperatures that people prefer for indoor settings, which feel comfortable when wearing typical indoor clothing. As a medical definition, the range generally considered to be suitable for human occupancy is between 15 degrees Celsius (59 degrees Fahrenheit) and 25 °C (77 °F), though human comfort can extend somewhat beyond this range depending on factors such as humidity and air circulation. In certain fields, like science and engineering, and within a particular context, "room temperature" can have varying agreed upon values for temperature.
The American Heritage Dictionary of the English Language identifies room temperature as around 20 to 22 °C (68 to 72 °F), and the Oxford English Dictionary claims that it is "conventionally taken as about 20 °C (68 °F)".
Owing to variations in humidity and likely clothing, recommendations for summer and winter may vary; a suggested typical range for summer is 23 to 25.5 °C (73 to 78 °F), with that for winter being 20 to 23.5 °C (68 to 74 °F), although by other considerations the maximum should be below 24 °C (75 °F) – and for sick building syndrome avoidance, below 22 °C (72 °F).
The World Health Organisation's standard for warmth is 18 °C (64 °F) for normal, healthy adults who are appropriately dressed. For those with respiratory problems or allergies, they recommend a minimum of 16 °C (61 °F), and for the sick, disabled, very old or very young, a minimum of 20 °C (68 °F).
Ambient versus room temperature
Ambient temperature simply means "the temperature of the surrounding air"; in a room it is the temperature of the air in that room. Room temperature is not necessarily the same as the temperature of the air in a room. If a room is uncomfortably cool or warm, then the ambient temperature is significantly lower or higher than room temperature.[clarification needed]
Serving temperature of red wine
A common piece of advice is to serve red wine "at room temperature". This advice stems from a time from before central heating, when room temperature in wine-drinking countries was considerably lower than it is today, usually in the range between 15 °C (59 °F) and 18 °C (64 °F). The advice is therefore to serve the wine at, at most, about 18 °C (64 °F).
- Merriam Webster's Medical Dictionary. 2016. Archived from the original on 2010-04-10.
- "Archived copy". Archived from the original on 2017-09-20. Retrieved 2017-09-19.
- The American Heritage Dictionary of the English Language (5th ed.). 2014. Archived from the original on 2015-01-08.
- Oxford English Dictionary, Third Edition, November 2010), sub-entry at room.
- Burroughs, H. E.; Hansen, Shirley (2011). Managing Indoor Air Quality. Fairmont Press. pp. 149–151. Archived from the original on 20 September 2014. Retrieved 25 December 2014.
- "BBC News Magazine: How warm is your home". Archived from the original on 2017-12-31.
- Karen MacNeil (2015). The Wine Bible (revised second ed.). Workman Publishing. p. 130. ISBN 978-0-7611-8715-8.