A vigil (from the Latin vigilia, meaning wakefulness) is a period of purposeful sleeplessness, an occasion for devotional watching, or an observance. It can also be the eve of a religious festival observed by staying awake as a devotional exercise or ritual devotions observed on the eve of a holy day. A vigil is often held when someone is gravely ill or dying. Prayers are said and votives are often made. Vigils extend from eventual death to burial, ritualistically to pray for a loved one, but more practically so they are never alone.
Note to self - One book talks about incenses and candles for the vigilers. Gotta watch the smells and bells mix with the oxygen use. Or we will all go to "kingdom come" together.