How long should you wait before washing the walls in a bedrom after painting?

If it's water base paint and your doors or Windows are open while painting it dries quickly and you can sleep in the room the same evening. I am painting my bedroom and stop around dinner and have had the Windows open and it's safe to sleep and I've done so. If it's oil base paint (enamel paint) it's generally strong in odor and although not hazardous to your health it can cause headaches in some people or sinus problems. I'd wait a good 24 hours. Meanwhile, when you use oil base paint put 1 teaspoon of vanilla flavoring in the oil paint and stir well. This helps cut down the strong odor. After 24 or even 48 hours of airing the room out during the day ONLY and not at night (for safeties sake) you can spray Febreeze in the room to kill any remaining odors or burn (safely) incense or perfumed candles.