Somehow, the vow you made last year — to never again suffer through another sweltering summer — lost its urgency after a winter of cold feet. And despite spring's mild temperatures, here's fair warning: Don't put off buying today what you're sure to want in the coming weeks — an air conditioner.

"That first hot day, the phones just ring off the hook," says Tim White, president of A-1 Mechanical in Lansing. "It's going to get warm, and if it stays warm, you're going to have to wait."