Fires can happen anywhere and at any time. Even though modern homes have smoke detectors, many people still worry about what would happen if a fire started while they were asleep. Would the smoke wake them up in time to escape? Or would they sleep through it until it was too late? In this article, we will look at the factors that determine whether someone is likely to wake up during a fire, and steps people can take to improve their chances of getting out safely.
Do smoke alarms work to wake people up?
Smoke alarms are designed to detect smoke and sound an alarm to alert occupants of danger. However, research shows that smoke alarms alone may not be enough to reliably wake up everyone sleeping.
In a landmark study by J.M. Bruck and V.L. Thomas in 2012, the researchers found that over 50% of children and teens ages 5-17 and over 75% of adults failed to wake up to the sound of a smoke alarm. Other studies have confirmed that smoke alarms frequently fail to rouse people from sleep, especially children, teens, the elderly, and people who are intoxicated from alcohol or drugs.
So while smoke alarms are essential for detecting fires, they do not guarantee that sleepers will be alerted in time to escape. Additional measures may be needed to improve the odds of waking up.
What factors affect ability to wake up to fire cues?
There are several factors that influence a person’s likelihood of waking up to fire cues such as smoke alarms or the smell of smoke while asleep:
– Age – As mentioned, children and teens are less responsive to auditory alarms during sleep. The elderly also have higher arousal thresholds.
– Alcohol or drug use – Intoxicants depress the nervous system, making it harder to rouse from sleep.
– Sleep stage – People are most difficult to awaken when in deep, non-REM sleep stages.
– Medications – Some prescription medicines like sleeping pills inhibit awakenings.
– Hearing impairment – Those with hearing loss may not hear alarms.
– Proximity to alarm – Alarms are louder near the source. Bedroom doors should be closed at night so alarms can penetrate rooms.
Knowing these risk factors can help people identify who in a home may need extra assistance waking during a fire emergency.
Would the smell of smoke wake you up?
Some hope that even if they sleep through a smoke alarm, the smell of smoke would wake them up in time. But studies show that aroma may not be enough to cause awakening either, especially given most modern fires generate little scent initially as they spread.
Researchers have measured arousal thresholds by piping smoke-like odors into sleep lab rooms. They found that people often continue sleeping even when smoke-like smells reach or exceed alerting levels. This tolerance effect is especially strong after prolonged exposure during sleep.
So while the stench of smoke may eventually cause someone to stir, waiting for smell risks exposure to dangerous levels of toxic gases that numbs the senses. Smoke alarms remain the first and fastest line of defense.
Would you wake up faster to your own name?
Perhaps calling out to sleepers by name could provide a better chance of waking up?
A study by Bruck in 2007 tested this by playing recordings of various fire cues, including a mother’s voice, during sleep. The researchers found no significant improvement in responsiveness when using the personalized maternal voice over tones or alarms.
However, the voice recordings were limited to simple statements, not urgent yelling of the child’s name. Parents speculate that repeatedly shouting a child’s name while shaking them would be more effective than disembodied recordings at rousing kids from slumber during a fire. But this has not been scientifically verified.
What else can improve the odds of waking up?
While smoke alarms are not foolproof, there are steps people can take to improve their chances of being alerted in time to escape a fire:
Install smoke alarms properly
– Put smoke alarms on every level of the home and inside each bedroom.
– Use interconnected alarms. When one sounds, they all sound.
– Test alarms monthly and replace batteries yearly.
– Replace alarms every 10 years.
Use strobe light and bed shaker alarms
– Add strobe light alarms that flash with sound. The lights can help wake heavy sleepers.
– Use bed shakers or pillow vibrators triggered by alarms to physically stir sleepers.
– Consider a wireless system to place alarms nearer to sleep areas.
Close bedroom doors at night
Shutting doors helps block noise and keep alarms within earshot.
Practice home fire drills
– Hold regular fire drills so everyone knows the evacuation plan by rote.
– Teach children what smoke alarms sound like so it is familiar.
– Know two ways out of every room and designate an outside meeting place.
Keep keys and shoes by bed
If trapped, you may need keys to escape and shoes to run through debris.
Who is most at risk of not waking up?
While every sleeper is vulnerable to some degree, these groups face the highest risk of not waking up or responding slowly to fire cues:
Children
Studies show children under 14, especially those under 5 years old, are the least likely age group to wake up to smoke alarms. Their immature neurological systems make rousing from sleep more difficult.
Teenagers
Teens need more sleep but have trouble falling asleep early. As a result, they accrue “sleep debt” that makes awakening harder. Many teens also sleep with phones, tuning out stimuli.
Older adults
Arousal mechanisms weaken with age, leading to higher arousal thresholds in seniors. Hearing loss and certain medications also inhibit waking up.
Intoxicated individuals
Consuming alcohol before bed makes people harder to wake up and respond to threats. Illicit drug use has similar sedative effects.
Those taking medication
Many prescription and over-the-counter drugs promote deeper sleep from which it is harder to rouse. These include sleeping pills, antidepressants, antihistamines, and others.
Are there devices to help high risk individuals wake up?
Because children, heavy sleepers, and the hearing impaired may sleep through standard alarms, specialized devices exist to help these high risk individuals wake up to fire cues:
Wearable vibration devices
Worn on the wrist or ankle while sleeping, these devices vibrate to alert the wearer when triggered by a smoke or CO alarm. The sensation helps break through deep sleep.
Pillow or bed shakers
Shakers placed under the pillow or mattress pad produce strong, localized vibration to physically stir someone to wake them.
Low frequency alarm sounders
These specialized alarms emit a low-pitched sound at 520 Hz, which is harder for people to sleep through.
Flashing strobe lights
Strobes activated by alarms provide a visual cue making it harder to sleep through the danger. Useful for the hard of hearing.
Smart alerting devices
Networked smart home systems allow customized multi-sensory alarm activation, like playing a loud voice message saying “Wake up, there is smoke in the house!” along with flashing lights.
Conclusion
Waking up to fire cues like smoke alarms relies on both the strength of the stimuli and each person’s ability to rouse from slumber. While alarms are critical for detecting danger, sole reliance on auditory alarms is unwise given their limitations. Using visual, tactile, and voice cues can significantly improve the odds of waking up and escaping a nighttime fire, especially for high risk groups like children, heavy sleepers, and the hearing impaired. Home fire drills are also essential to practice responding quickly when every second counts. Ultimately, layered sensory alarm methods combined with preparation offer the best chance at surviving a house fire