You might not think it particularly likely that your head will spontaneously catch fire, but it happens more often than you might think- at least in Latin literature. Just look at the following passages:
cum subitum dictuque oritur mirabile monstrum.namque manus inter maestorumque ora parentumecce levis summo de vertice visus Iulifundere lumen apex, tactuque innoxia mollislambere flamma comas et circum tempora pasci.nos pavidi trepidare metu crinemque flagrantemexcutere et sanctos restinguere fontibus ignis.Suddenly there was a
great miracle. At the very moment when we were both holding
Iulus and he was there between our sorrowing faces, look, a
light began to stream from the top of the pointed cap he was wearing and the
flame seemed to lick his soft hair and feed round his
temples without harming him. We took fright and rushed to beat out his
flaming hair and quench the
holy fire with water.
Aeneid II.680-686
praeterea, castis adolet dum altaria taedis,
et iuxta genitorem astat Lauinia virgo,
visa (nefas) longis comprendere crinibus ignem
atque omnem ornatum flamma crepitante cremari,
regalisque accensa comas, accensa coronam
insignem gemmis; tum fumida lumine fulvo
involui ac totis Volcanum spargere tectis.
What's more, when
Lavinia was standing by her father's side tending the altar with her chaste torches, another fearful sight was seen. Her long hair caught fire and all its adornment was crackling in the flames. The princess's hair was blazing, her crown with all its lovely jewels was blazing, and soon she was wrapped in smoke and yellow glare, and scattering fire all over the palace.
Aeneid VII.71-77
Eo tempore in regia prodigium visu euentuque mirabile fuit. Puero dormienti, cui Servio Tullio fuit nomen, caput arsisse ferunt multorum in conspectu; plurimo igitur clamore inde ad tantae rei miraculum orto excitos reges, et cum quidam familiarium aquam ad restinguendum ferret, ab regina retentum, sedatoque eam tumultu moveri vetuisse puerum donec sua sponte experrectus esset; mox cum somno et flammam abisse.
In the palace about that time there occurred a very odd thing, which was to have remarkable consequences. A little
boy named
Servius Tullius was
lying asleep, when his
head burst into flames. Many people saw it happen. The
noise and excitement caused by such an
extraordinary event came to the ears of the king and queen, and brought them hurrying to the spot. A servant ran for
water and was about to throw it on the flames, when the queen stopped him, declaring, as soon as she could make herself heard, that the
boy must on no account be disturbed, but allowed to sleep till he awoke of his own accord. A few minutes later he opened his eyes, and the fire went out.
Livy I.39
In fact, having your head catch fire is not so bad (
Michael Jackson aside). For Iulus, Lavinia and Servius Tullius it was actually a sign of the gods' favour towards them. Through the sign of fire they confirm Iulus' destiny to grow up to be a great king of Italy, Lavinia's destiny to marry the foreign hero Aeneas and Servius Tullius' destiny to become king of Rome.