A fallen hem when you're headed out the door is a hassle. You probably don't have enough time to take your piece to a tailor, but you can't leave the house looking less than put-together. Take another sip of coffee and don't panic. A temporary fix is quick with a few supplies you might want to keep on hand for just such occasions.
Double-Stick Fabric Tape
Apply double-stick fabric tape, which adheres to either side of your hem and will temporarily keep it in place. This tape is specifically made to work with fabric. Don't substitute regular double-stick tape, which can leave you with a sloppy result. Simply place the tape on the section of the hem that has fallen, fold over the hem and firmly press down to seal. Fabric tape can be removed easily and should keep your hem bonded through the day.
If you have pants that every now and then you'd like to make shorter -- say to temporarily switch out heels for flats on your walk to work -- use fabric magnets. Magnets come in three sizes -- roughly 1/2-, 3/4-, and 1-inch wide each. The magnets are shaped like coins and come in matching sets -- one with a positive charge and one with a negative one. One magnet is placed on the inside of the hem and the other on the outside of your pant. The number of magnets you use will depend on the length of your hem, so you may need more than just one set. Sewing magnets can be found at online retailers and in crafts and fabric stores.
Fabric adhesive is a heavy-duty glue that can keep your hem securely in place. Apply the adhesive to two-inch sections of the hem at a time, folding the our fabric over and pressing it securely as you go. Some fabric adhesives are permanent, while others are temporary. If you don't want your hem glued forever, opt for the temporary version. Fabric adhesive is available at craft and fabric stores.
Needle and Thread
If you're feeling industrious, do a temporary hem stitch. Turn your pants inside out and pin them to the desired length. Using a thread that's about the weight of your pant, sew in a looping motion through the hem and the inner part of your pant, until you've mended the entire hem. Leave a couple of inches between each stitch to speed things up and make removal fast and simple.