Run a fever ＝發燒
Cantonese Pinyin: faat3 siu1
A：Oh man, your forehead feels hot. You’re running a fever!
B：Oh no, not again. Only when I’m on holiday!
Contrary to the western culture inclining to cool down a fever patient with cold water and ice bag, Chinese traditions do the opposite – wrapping the patient up in a warm duvet in order to break out in a sweat.
When 「緊」describes an action, it is akin to –ing form in English language’s present continuous tense.
e.g. 發緊燒 (having fever)
e.g. 食緊野 (eating)
e.g. 做緊咩? (doing what)