If I were you, I'd concentrate on long term more so than short term.
SuperSally provided good advice, but 225 is not that high as to be life-threatening. You can jog for an hour. See your doctor as soon as possible.
Hi,
the quick fix for high blood sugar is injected insulin. This will bring down sugars in a couple of hours. However, you must be trained and learn how to effectively and safely use insulin, which is a very powerful medication.
Without insulin: drink lots of water, eat nothing with carbs in it, exercise (walking may be ideal).
If your blood sugars are consistently this high, please see your dr and get properly treated. Low carb diet, exercise, and being sure that body weight is optimal are the natural ways to treat diabetes. If this is not enough, then medication (oral or insulin) are necessary.
Please do get this look at and properly managed for the sake of your health.