Claim: Shirt of Flame refers to a specific form of the tar, pitch and oil doused and set alight poison dress trope in folklore which were used on Christians and martyrs in the Roman Empire.
Evidence: The phrase Shirt of Flame refers either to a specific form of the poison dress trope in folklore, or to a particular type of clothing given to people about to face burning at the stake. During the Persecution of Christians in the Roman Empire, many early Christians were executed by being doused with tar, pitch and oil, and set alight in Rome. Many Protestants were later sentenced to "death by burning" in 16th-century England because of their faith.