The Shadowhunter's Codex by Cassandra Clare, Joshua Lewis Page A

vulnerable to fire. While they are much stronger and more durable in many ways than mundanes and Nephilim, their bodies are weaker and less resistant to burning than humans’. They are likely, when exposed to fire, to burst into flames in the manner of paper, dry wood, or similarly flammable objects. As such, vampires not only can be harmed by fire but can often be kept at bay by a protective boundary of fire or a burning torch.
Holy water, and other common blessed materials, such as angelically aligned swords, are harmful to vampires and will scorch and burn their flesh.
More generally, holy symbols may be anathema to vampires if the symbols hold weight with the specific vampire addressed. A crucifix may repel a vampire who held Christian beliefs before he was Turned, but a vampire who was raised as a person in a Buddhist faith would not generally respond. In the early days of vampire hunting, when there was much less migration of peoples away from their home cultures, holy symbols were more dependable as vampire repellent, but in our modern age of religious pluralism and because of the ease with which people can move around the world, it has become unwise to depend on this method.
Along similar lines, older guidebooks to the Shadow World suggest that a vampire trying to hide his demonic nature can be sussed out by his inability to speak the name of God. This is also no longer reliably true. Most vampires that as mortals did not ascribe to a religious faith do not develop an aversion to holy names as part of their Turning. In addition, older and more powerful vampires often regain the ability to speak holy names, although it’s not clear whether this is because the aversion fades over time or because as the vampires age, they descend more deeply into the demonic and become able to speak God’s name as a curse.
As mentioned before, vampires cannot stand the direct light of the sun. Mythology tells us that this is a facet of their status as demonic, damned creatures, that they are cursed to not be able to look at the sun that gives life to Earth. Whatever the reason, sunlight burns the skin of vampires, as does (to a lesser extent) witchlight, being light of angelic origin. Artificial light, such as that of gaslight and electric light, may cause discomfort in vampires if it is strong enough, but they are normally able to remain undamaged unless already very weak. Also fluorescent light is avoided, as it’s unflattering.
A ray of sunlight will cause burns on a vampire’s skin, but full exposure to the sun—being exposed fully to unblocked sunshine—will cause them to burst into flame dramatically, and they will be consumed and put to rest quickly. For this reason vampires are normally careful to remain dormant and inactive during daylight hours. Unless he is a SUPERVAMPIRE, of course.
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TREATING VAMPIRE BITES
    Important! Note!
    Why’s it gotta be like that, man?
If a vampire bites and drinks blood from a victim, no supernatural treatment may be needed. Normal Shadowhunter wound-care protocols apply—the use of an iratze or other healing Marks, and treatment for blood loss and shock if the draining has been severe. Mundanes also can have their blood taken by vampires with no permanent ill effects, provided the wounds are cared for and not too much blood has been taken.
The real danger lies in the case of a human who has consumed vampire blood. Even if not enough blood is consumed to cause the death and rebirth of the victim as a vampire, the smallest amount of vampire blood is enough to create in the victim an irresistible pull to vampires, which could cause that victim to become a subjugate, begging to be Turned.
The proper treatment for the consumption of vampire blood is emetic: The victim must be made to drink holy water until all of the vampire blood is out of his system. The victim is likely to be very sick during this process—he will of course cough up everything in his system, not just the vampire blood, and