In a hadith, the Prophet is quoted as saying,

A person who sleeps on a rooftop without edges and falls and dies, has no claim. Similarly, a person who sails in the sea when it is rough and dies, forfeits all claims. (Al-Bukhari and Ahmad)

The Prophet impresses on his Companions, and indeed on all Muslims, that they should take normal precautions against what causes harm to them. Thus Muslims should take any measure that enhance their safety or the safety of their family and dependants. If someone fails to take such measures, they forfeit any rights they might have been entitled to have, from other people or from Allah because of their failure. We have a hadith that clearly speaks against sleeping on an open roof: "Anyone who sleeps on a rooftop with no barriers forfeits all claims." (Al-Bukhari and Ahmad)

In our modern days when we have air-conditioning and comfortable beds, we may wonder who wants to sleep on a rooftop. We need only to go back a little bit in time and imagine a place with a very hot climate and with no air-conditioning available. Many people preferred to sleep on the roofs of their homes because it felt far more comfortable than sleeping in their bedrooms that were much hotter.

In this hadith, the Prophet tells us very clearly that we must take reasonable precautions against a fall. To start with, he points out that if the rooftop is without a reasonable barrier, then sleeping there is wrong. Sleepers may be exposed to certain risks. If they turn over and happen to be near the edge, they might fall down. A fall is also possible if they wake up and start to walk before they are completely alert. Or they might trip over something in the dark and fall as a result, causing themselves serious injury. Therefore, Muslims must not expose themselves to the risk of falling.

Allah is generous and compassionate to us, assigning angels to watch over us. We see this clearly in situations of imminent danger that we have overlooked. We suddenly are alert to the danger and take a reflex action to avoid trouble. We wonder how we could see the danger in the nick of time, when all factors should have prevented us from doing so. Take the example of someone driving alone and getting tired. They may be about to fall asleep when something suddenly alerts them. Allah says in the Qur'an "There are guardians watching over you, noble recorders, who know all your actions" (Al-Infitar 82:10-12).

But in order to be in the safest position, we need to take all reasonable precautions in every situation. Thus, we should not drive long distances when we are tired.. Instead, we should have some sleep before we start our journey. In the same way, people who sleep on a rooftop without a raised edge or a barrier to prevent a fall should take reasonable precautions. If they do not and they fall to their death, no claim can be made against anyone. Moreover, they may have forfeited any reward they would have otherwise received. If they take proper precautions and pray to Allah for their own safety but they nevertheless meet their destiny by a fall, they will be considered a martyr and receive a good reward.

This was perfectly understood by the Prophet's Companions. Abu Ayyub Al-Ansari, a Companion of the Prophet, visited a friend who took him to the roof which had no wall edges. Apparently, the friend offered him to sleep there. But Abu Ayyub declined and went down. He said, "I was about to stay the night forfeiting all I have" (Al-Bukhari).

The opening hadith here mentions two types of exposure to danger. In both situations someone does something careless as a result of which he forfeits all his rights. There is first the right to be helped by the guardian angels and the right of reward that results from such danger.

Although the Prophet mentions only these two types, the import of the hadith is clearly applicable to all types of danger. One of these is exposure to illness. Some diseases are contracted through careless behavior while others are caused through the failure to take preventive measures. Nowadays, we have vaccinations against a variety of diseases, including some of the worst diseases that affect children, such as tuberculosis, measles, and whooping cough. If we fail to vaccinate our children at the right time, we are not giving them the immunity that spares them much trouble. Some of these diseases are killers. If parents fail to immunize their children through vaccination, they are exposing them to these killer diseases. They risk coming under the Qur'anic verse that states "Losers indeed are those who, in their ignorance, foolishly kill their children" (Al-An`am 6:140).

Failure to immunize children when the means are available could be through either negligence or ignorance. Neither is valid justification. So if parents neglect to vaccinate their children, and as a result, a child contracts a disease which ends in the child's death, the parents have to answer to Allah for a very serious failure.