room temperature
noun [ U ] uk/ˈruːm ˌtem.prə.tʃər/ us/ˈruːm ˌtem.pɚ.ə.tʃɚ/
室温，常温
the temperature that is normal inside a building, neither very hot nor very cold
Put the dessert in the refrigerator, because it will not set at room temperature. 把这些甜品放进冰箱里，因为在常温下凝固不起来。