When the milk comes to the boil, turn off the heat.

【heat】牛奶煮沸后把火关掉。

So, we put the washing in the copper here when it's quite an average temperature and then we wait for the temperature to come to the boil.

所以，我们要在温度差不多时，把洗好的衣服放在这里的铜锅里，然后等待水温升高至沸腾。