Colloquially, room temperature is the range of air temperatures that most people prefer for indoor settings, which feel comfortable when wearing typical indoor clothing. Human comfort can extend beyond this range depending on humidity, air circulation and other factors. In certain fields, like science and engineering, and within a particular context, room temperature can mean different agreed-on ranges. In contrast, ambient temperature is the actual temperature of the air in any particular place, as measured by a thermometer. It may be very different from usual room temperature, for example an unheated room in winter.
Comfort temperatures
The American Heritage Dictionary of the English Language identifies room temperature as around, while the Oxford English Dictionary states that it is "conventionally taken as about ". Owing to variations in humidity and likely clothing, recommendations for summer and winter may vary; a suggested typical range for summer is, with that for winter being, although by other considerations the maximum should be below – and to avoid sick building syndrome, below. Some studies have suggested that thermal comfort preferences of men and women may differ significantly, with women on average preferring higher ambient temperatures.
Health effects
The World Health Organization in 1987 found that comfortable indoor temperatures between were not associated with health risks for healthy adults with appropriate clothing, humidity, and other factors. For infants, the very elderly, and those with significant health problems, a minimum was recommended. Temperatures lower than with humidity above 65% were associated with respiratory hazards including allergies. The WHO's 2018 guidelines give a strong recommendation that a minimum of is a "safe and well-balanced indoor temperature to protect the health of general populations during cold seasons", while a higher minimum may be necessary for vulnerable groups including children, the elderly, and people with cardiorespiratory disease and other chronic illnesses. The recommendation regarding risk of exposure to high indoor temperatures is only "conditional". Minimal-risk high temperatures range from about depending on the region, with maximum acceptable temperatures between.
Temperature ranges are defined as room temperature for certain products and processes in industry, science, and consumer goods. For instance, for the shipping and storage of pharmaceuticals, the United States Pharmacopeia-National Formulary defines controlled room temperature as between, with excursions between allowed, provided the mean kinetic temperature does not exceed. The European Pharmacopoeia defines it as being simply, and the Japanese Pharmacopeia defines "ordinary temperature" as, with room temperature being. Merriam-Webster gives as a medical definition a range of as being suitable for human occupancy, and at which laboratory experiments are usually performed.
Serving temperature of red wine
People traditionally serve red wine at room temperature. This practice dates from before central heating, when room temperature in wine-drinking countries was considerably lower than it is today, usually in the range between and. It is therefore advised to serve red wine at a temperature of at most.
