Mr. Freeze captures Batman and Robin underneath the Bruce Wayne Ice Arena. He puts them in a sub-zero temperature vaporizing cabinet, and starts lowering the temperature inside. When they are cold enough, he will activate the vaporizing pipe pump, which will vaporize them directly into the ice surface above.
"What fiendish freezing isometric exercise is this? Stay frozen to your furniture!"
Batman remembers that there is an emergency exit in the refrigeration system (the building is named after him, after all). The cabinet frosts up when Freeze activates the pump, and Batman and Robin escape out the back.
With an instant freeze formula, Mr. Freeze threatens all of Gotham City.