This is why before the rocket is fired, the people have it on their wrist, in their pocket or in their hand, waving it in the air when the person responsible for starting the festival shouts, "Viva San Fermín, Gora San Fermín". When the festival begins, the scarf takes its place on one's neck or head, as imagination and fashion would see fit.
In addition to looking good with white and staining one's clothes, if it is poor quality and you wash it with lights at over thirty degrees, the scarf has a religious origin. According to the parish priest of the San Lorenzo Church in Pamplona, where the chapel is in honour of San Fermín, Jesús Labari, "We are not absolutely sure and there are no facts to prove the time when the scarf began to be used, but we do know the reasons for it. For religious ceremonies in honour of a saint, if the saint is a martyr and died for his beliefs, the priests dress in red. In the case of the festival in honour of San Fermín, we do this because he was martyred and the thing about the red scarf is a performance by the people of this religious custom."
It is known that the red scarf isearlier than the custom of dressing in white, which is more recent. In fact, when he was mayor of Pamplona in the sixties, Miguel Javier Urmeneta encouraged the groups to spread the use of white dress, and managed it.
There are many other theories behind the thing about the scarves. Some believe that it is to call the bulls, as it seems that they are attracted by red. It must be remembered that in the ‘encierro' it is recommended to run without a waistband and scarf because the bull could catch you right there, so this theory is not supported by many people.
Other people in Pamplona back the idea of the scarf as a custom of the city of Pamplona, which would give weight to the martyrdom of San Fermín, which is the thing about the Vow of the Five Wounds. This was established in 1599 as an act of gratitude for the eradication of a plague that killed a third of the population in Pamplona. More effective than the medicines, of which there were none, was to place a sign on the chests of the sick representing the five wounds of Christ. Given the effectiveness of the measure and in thanks, the city authorities decided to permanently celebrate this vow called "of the Five Wounds", which is precisely very similar to a scarf around the neck.