本句中译就是俗称的「打铁趁热、把握良机」
以下回答是根据
http://wiki.answers.com/Q/What_is_meant_by_...he_iron_is_hot'的说明
Strike while the iron is hot.
This idiom is used to mean that the topic of the conversation should be carried out before that opportunity is lost forever.
这个机会是有失去的风险存在
'Striking when the iron is hot' is a metaphor that refers to taking an opportunity when it arises.
这个机会是没有失去的风险
该网页有例句 有兴趣请参考
个人意见:用while而不是用when是因为这是惯用语法 除了记诵别无他法 XD