Of course, but keep in mind that this will shorten the lifespan of your extensions. As it is with your natural hair, apply heat regularly to extensions can damage the hair or dry it out. So, it's best to limit how often you apply heat to your extensions. In fact, the best way to dry your hair is to sit up a dryer or let it air dry. Then, for those times when you're in a rush, use blow drying, but low heat.