Dust and dust mites are common indoor allergens, so when winter comes (and you spend more time indoors) these allergy symptoms may worsen. The best way to combat the allergy symptoms is to prevent (or minimize) your exposure to the allergen in the first place. Strategies to reduce the dust and dust mites in your home include: Purchase a HEPA air filter. This can help to clear dust out of the air, and hence reduce your allergy symptoms. Wash your bedding at least once a week in hot water. This can help to prevent the accumulation of dust and dust mites. Also use allergy-proof covers on your mattress and pillow covers to reduce the accumulation of dust and dust mites. Vacuum any carpets in the home at least twice a week, and clean any surfaces that gather dust regularly. Use a wet paper towel or sponge to clean these surfaces a duster will just cause the dust to recirculate and settle again. Another common allergen that can worsen during the wintertime (due to its presence indoors) is mold. Mold grows in damp places, such as around leaks in roofs or pipes, in the shower or bathroom, or anywhere with moisture. Strategies to reduce your exposure to mold include: Throw out any shower curtains, carpets, or other things in your home that have mold on them. If you spot mold on something, your best bet is just to get rid of it. The longer it lingers in your home, the more of a chance there is for mold spores to get into the air and to worsen your allergy symptoms. Use a dehumidifier to reduce the humidity in your home to less than 50%. Because mold thrives with greater moisture and humidity, this can help to prevent mold problems from developing in your home. Both pets and people may spend more time indoors during the winter, so if you are allergic to dogs or cats you may find that your allergy symptoms worsen during the colder months. If you have severe pet allergies, consider getting a non-hairy pet instead such as a fish or lizard. If you only have mild pet allergies and are seeking to manage them as best as possible, you can try: Washing your pet at least once a week. This is because, contrary to popular belief, pet hair is not the most common allergen; rather, it is pet dander (dead skin cells that naturally shed from your pet). For this reason, bathing your pet can help to diminish the dander and reduce your allergy symptoms. Keeping your pet out of the bedroom. Because you spend quite a bit of time in the bedroom every night, as well as the fact that bedrooms are often carpeted, keeping your pet out can prevent pet dander from accumulating in your bedroom. This, in turn, can help to alleviate your allergy symptoms. As the holidays approach, there are some additional steps you can take to handle your allergies and prevent them from getting out of control. These include: Getting an artificial Christmas tree because real trees have the potential to grow mold. Some people are also allergic to the fragrance of a real tree. If you do get a real tree, consider washing it thoroughly with water outdoors before you bring it in and decorate it. If you are visiting relatives for the holidays who have a pet (and you are allergic), plan appropriately by asking for a room as far away as possible from the pet, and by bringing allergy medications as needed. Be aware of the rebound effect if you are not spending the holidays with your own pet. Some people, after being away from their pet for several days, return home only to find that their allergy to their own pet has worsened. This is due to a decreased tolerance in your immune system following your absence. Understand that stress can trigger allergy symptoms such as hives or asthma. Try to stay as relaxed as possible over the holidays, and take steps to lighten your workload during the holidays (such as preparing some of the dishes for big dinners in advance). Some people confuse the runny nose they get from being outside in the cold with a winter allergy when, in fact, the two are not related. A runny nose in the cold is a vasomotor (physiological) response; it may be correlated to changes in temperature (particularly the cold), windy weather, changes in humidity, and strong odors or smoke.

Summary: Minimize your exposure to dust and dust mites. Get rid of any mold around your home. Practice good hygiene with your pet. Plan for the holidays. Know that a runny nose from being outdoors is not an allergy.

If you want to, you can put the shirt on to determine the new length. Keep in mind that your shirt will be about to 1 inch (1.27 to 2.54 centimeters) longer, depending on how wide the original hem is. Spread the shirt out on a flat, even surface, right-side-out. Use a ruler to measure up from the bottom edge of the shirt every so often. This will ensure that your shirt is the same length all the way around. If you can't find a dressmaker's chalk or pen, you can make the line using sewing pins instead; just be careful not to pin both sides of the shirt together. Keep folding your way all around the shirt. It should now be a little shorter than before. You are still folding on the outside of the shirt. Do not fold the hem on the inside. Use the zigzag stitch or the stretch stitch on your sewing machine. Make sure that your thread color closely matches your shirt. Keep your shirt right-side-out. You should now see the original hem, the hem's original stitching, and your new "seam" just above it. Focus on the new seam you made. This will flatten it, and make the bottom of your shirt smoother. If you'd like, you an secure the hem with sewing pins, although this is not necessary. Anywhere between to 3/16-inch (3.2 to 4.3 millimeters) away will be plenty.Use a stretch stitch for this step, and be sure to go back and forth over the start and end of your sewing a few times to prevent unraveling. Start sewing from one of the side seams. This will help hide the start and end of your sewing better. If you secured your hem with sewing pins, be sure to pull them out as you sew. Try to cut as close to your stitching as you can. Discard the excess material, or save it for another project. When you are done, go back over your shirt and snip off any excess or loose threads. Your shirt is now ready to wear.
Summary: Figure out how short you want your shirt to be, and make a mark on the outside of the shirt. Use a dressmaker's chalk or pen to draw a line all around the shirt at an even distance from the bottom edge. Fold the hem up until the bottom edge touches the line that you drew. Sew around shirt, as close to the selvage edge as you can. Fold hem back down, and tuck the excess fabric inside the shirt, away from the bottom of the hem. Press the hem with an iron. Top stitch as close to your seam as possible. Turn the shirt inside-out and cut the excess material away. Turn shirt right-side-out.