This appliance helps you wake up feeling fitter and more energetic. It creates a summer dawn
experience that makes awakening and getting up easier. The light intensity slowly increases to the
chosen level during 30 minutes. Light reduces the level of the sleep hormone melatonin and
increases the production of the cortisol hormone that makes you feel more energetic when you
wake up. You can have the appliance wake you up by light only or by light and sound. The appliance
can also be used as a reading lamp.
light and the biological clock
Exposure to light regulates the biological clock that controls the body's circadian rhythms. The
melatonin level rises in the evening, preparing our body for sleep and lowering the body
temperature. The light in the morning stimulates the secretion of the hormone cortisol, which makes
us awake and alert. Optimally, the circadian rhythms are in sync with our sleep-wake rhythm.
Disturbed sleep and circadian rhythms can severely impact our health, performance and productivity.
In autumn and winter, when the days are shorter and darker, many people experience tiredness and
need more sleep. Lack of energy and trouble to get up in the morning are common symptoms of
the winter blues. Other symptoms may be unexpected mood changes, concentration problems and
a craving for food rich in fattening carbohydrates. Some people may even develop a serious
depression (seasonal affective disorder or SAD), which disappears when spring comes.
the effects of dawn simulation
Hypersomnia is associated with a phase delay of the circadian rhythm. The Philips Wake-up Light
regulates the circadian rhythm during the last half hour of sleep. In the early morning hours, our eyes
are more sensitive to light than when we are awake. During that period, the relatively low light levels
of a simulated natural sunrise are sufficient to phase-advance our biological clock, to suppress the
melatonin production and to elevate the cortisol level upon awakening. Clinical studies have shown
that regular use of a dawn simulator can alleviate even the severest symptoms of the winter blues.
People who use the Wake-up Light wake up more easily and feel more energetic. Their overall
mood, productivity and ability to concentrate are improved. With the Philips Wake-up Light, you can
set the light level that corresponds to your light sensitivity for optimum dawn simulation.
For more information about the health benefits, see www.philips.com, search word "Wake-up Light".
general description (Fig. 1)
Top control panel
SNOOZE/SCREEN BRIGHTNESS CONTROL button
@& button (light on/off)
3 button (light and sound on/off)
# button (sound off)
100W lamp (HF3462, HF3461) or 75W lamp (HF3451)
Lamp replacement hatch
Bottom control panel
@ wheel (turn to set the light intensity)
RADIO button (HF3462, HF3461 only)
QUICK CHECK button
$ wheel (turn to set volume)