1
general::
Take advantage of favorable conditions, as in They just made a huge profit, so let's strike while the iron is hot and ask for some money. This adage alludes to the blacksmith's forge. [Late 1300s] Also see MAKE HAY WHILE THE SUN SHINES.
American Heritage Idioms
2
general::
Phrase(s): Strike while the iron is hot.
Prov. When you have an opportunity to do something, do it before you lose your chance. • This is the best time in the last ten years to buy a house. Strike while the iron is hot. • Ask Lisa for a favor now, while she’s in a good mood. Strike while the iron is hot.
McGrawhill's American Idioms And Phrasal Verbs