Praise be to Allah.
The one who dies by burning is a martyr, because of the report narrated by Ahmad (23804), Abu Dawood (3111) and al-Nasaa’i (1846) from Jaabir ibn ‘Ateek (may Allah be pleased with him), according to which the Messenger of Allah (blessings and peace of Allah be upon him) said: What do you regard as martyrdom?” They said: Being killed for the sake of Allaah. The Messenger of Allaah (S) said: “Martyrdom is seven things besides being killed for the sake of Allaah. The one who dies of the plague is a martyr, the one who drowns is a martyr, the one who dies of pleurisy is a martyr, the one who dies of a stomach disease is a martyr, the one who is burned to death is a martyr, the one who dies beneath a collapsed building is a martyr, and the woman who dies in pregnancy is a martyr.”
Classed as saheeh by al-Albaani in Saheeh Abi Dawood.
It says in ‘Awn al-Ma‘bood Sharh Sunan Abi Dawood:
Al-Mat‘oon is the one who dies of the plague. The one who drowns is a martyr if his journey was for a permissible purpose. The one who dies of pleurisy – this refers to pain in a person’s side, which calmed down and the pain ceased at the time of death; one of its signs is pain under the ribs and difficulty in breathing, along with constant fever and coughing. It is more common in women, according to al-Qaari. Al-mabtoon (the one who dies of a stomach disease) refers to diarrhoea or dropsy or pain in the stomach. The one who is burned to death refers to one who dies in a fire. The one who dies beneath a collapsed building – this refers to falling walls and the like. The woman who dies in pregnancy – al-Khattaabi said: what this means is that she dies with a child in her womb. End quote.
And he said at the end: i.e., she dies with a child in her womb. And it was said: this phrase [in Arabic] may refer to the woman who dies a virgin. End quote.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) was asked: If a man of the civil defence dies as a result of being burned with fire when he was trying to put it out, is he regarded as a martyr?
He replied: Firstly, I say: everyone who dies by fire and is a Muslim is one of the martyrs, because the Prophet (blessings and peace of Allah be upon him) said: “the one who is burned to death is a martyr.” But we cannot say that So and so is a martyr because he died by burning, because we do not know. Rather we stay in general terms that everyone who dies by burning is a martyr, and if he was a firefighter then he will attain a greater reward, because the one who died seeking to put out a fire combined two things: he was burned to death and he was protecting his brothers. So in fact he has attained two rewards: the reward for protecting his Muslim brothers and the reward of martyrdom for being burned to death. But you should note that we do not testify for any particular individual, meaning for example, that if a person is burned to death in front of us, we say “the one who is burned to death is a martyr,” but we do not say “this man is a martyr.” Al-Bukhaari (may Allah have mercy on him) referred to this issue in his Saheeh and said: “Chapter: It cannot be said that So and so is a martyr.” Then he quoted as evidence for that the words of the Prophet (blessings and peace of Allah be upon him): “ … wounded for the sake of Allah; Allah knows best who is wounded for His sake.” He said: Allah knows best; therefore if Allah knows who is wounded for His sake, then we cannot testify for anyone; rather we say in general terms that the one who is killed for the sake of Allah is a martyr. Thus we differentiate between speaking in general terms and speaking in specific terms.
End quote from Majmoo‘ Fataawa Ibn ‘Uthaymeen (25/448)
And Allah knows best.