Milk is a very popular home remedy for heartburn. Well it may work fine during the day to soothe the stomach after heavy meal. But don’t use it before sleep to prevent nighttime heartburn. The problem is that milk is only effective for 30 or 40 minutes. Since it is a high calorie food which requires quite some energy to be digested your stomach will produce even more acid than milk originally neutralized. That is why if you had some milk before going to sleep to treat your heartburn you can expect a sleepless night.
I strongly recommend to replace it with water since it will dilute the acid and get it out of stomach faster.
Don’t try to get rid of heartburn by eating something (there are lots of beliefs that eating something will help heartburn). If it is something high calorie it will produce even more acid.
Best recommendation is to stay awake for 2-3 hours after your last meal. This will guarantee that you will go to sleep with an empty stomach and zero nighttime heartburn.
If you cannot stay awake for that long I strongly recommend getting wedge pillow. It will elevate your body in a way preventing acid from getting to your esophagus. Wedge pillow could be uncomfortable for some people but you don’t need to sleep on it entire night (except a case when you have a severe chronic heartburn which needs to be treated for several months). Usually you will need it only for first 2-3 hours of sleep.