熱氣 的普通話 講為 上火.
熱氣 / 上火 是中醫觀念, 在英語裡沒有對應詞. 有人用 heatiness 來表達. (例如以羅果子鹽宣稱有清熱氣功效, 英文說明就是 remove heatiness)
講得清楚一點, 試: A concept in traditional Chinese medicine to describe the state of body that is associated with syndromes including constipation, soar throat, acne, etc.
refer: http://www.brandsworld.com.sg/cms.www/main.aspx?sid=220