Room temperature

Room temperature is the range of air temperatures that most people feel comfortable in when they are inside a building and wearing normal clothes. What feels comfortable can change depending on how humid it is, how the air is moving, and other things around.

In some areas like science and engineering, room temperature might mean a special agreed-upon range. But the actual temperature you can measure with a thermometer, called ambient temperature, might be very different from this ideal room temperature. For example, an unheated room in winter could feel much colder.

Sometimes food and drinks are served at room temperature, which just means they are neither hot nor cold.

Comfort temperatures

Main article: Thermal comfort

People feel most comfortable in rooms that are not too hot or too cold. Scientists say this "neutral temperature" is when people feel just right, neither warm nor cool. Books like The American Heritage Dictionary of the English Language say room temperature is about 20–22 °C (68–72 °F), but this can change depending on where you live.

In places with hot climates, like Indonesia or Nigeria, people feel comfortable in warmer rooms—up to around 24–30 °C (75–86 °F). Even small changes in temperature, like half a degree, can be noticed. In summer, some suggest keeping rooms a bit warmer, around 23–25.5 °C (73–78 °F), while in winter, slightly cooler rooms, about 20–23.5 °C (68–74 °F), may feel better.

Health effects

See also: Sick building syndrome

The World Health Organization says that keeping indoor temperatures between 18–24 °C (64–75 °F) is safe for most healthy adults when they have the right clothing and conditions. For babies, older people, and those who are sick, it’s best to keep the temperature at least 20 °C (68 °F). If the temperature drops below 16 °C (61 °F) and the air is very humid, it can cause breathing problems.

In 2018, the WHO suggested that 18 °C (64 °F) is a good minimum temperature to keep everyone healthy during cold weather. For some groups, like children and older people, a higher temperature might be needed. For warm temperatures, staying between 21 to 30 °C (70 to 86 °F) is usually safe, with the highest comfortable temperature being around 25 to 32 °C (77 to 90 °F), depending on where you live.

Definitions in science and industry

In science and industry, "room temperature" can mean different temperature ranges for different products and processes. For example, when storing medicines, groups like the United States Pharmacopeia say the temperature should be between 20 and 25 °C (68 and 77 °F), but it can go a bit lower or higher sometimes. Other groups, like the European Pharmacopeia and the Japanese Pharmacopeia, have their own temperature ranges they use.

In subjects like physics and chemistry, scientists often think of room temperature as the normal temperature in a lab. For easy calculations, they might use 20 °C, 25 °C, or 300 K (which is about 26.85 °C).