wake-up call
noun [ C ] uk/ˈweɪk.ʌp ˌkɔːl/ us/ˈweɪk.ʌp ˌkɑːl/
警示，警钟
If something that happens is a wake-up call, it should make you realize that you need to take action to change a situation.
For the insurance industry, these floods were a wake-up call. 对保险业来说，这些洪水敲响了警钟。
（旅馆、酒店的）电话叫醒服务
a phone call that you arrange to be made, for example in a hotel, to wake you up at a certain time