Newsletter banner (2).png

Keeping the lights on...

This week I'm experimenting with the 'article' format again - let me know if you prefer this - have left the more technical bits at the end for those of you who asked for them -



As the UK shuts down under a blazing sun this week, here are simple ways you can use light to keep your cool - and even save energy too!

1/ Harness the hue-heat effect - choose ‘cool’ colour temperature light bulbs. That will help you feel more comfortable, even in a room that is hot.

2/ Rise and shine- Bright light in the morning can improve sleep - even on these sweaty nights. It's tempting to stay indoors but your body clock starts to lose track without a clear difference between bright days and dark nights. Gentle exercise first thing before it gets hot will do the trick- watering the window boxes or a gentle stroll. Bright ‘cool’ light even from artificial light sources is better than a cup of coffee to boost mood and alertness. Time outside will boost your store of vitamin D to keep you healthy and happy through the dark months to come- although that may seem hard to imagine right now!

3/ Power nap - Resist the urge to take a long siesta in the afternoon: the need to sleep builds up over the course of the day so if you release that pressure, you will find it even harder to drop off at night. Set the alarm and take a half-hour power nap sitting in a comfy chair in a quiet spot with subdued light but not completely dark - you won’t have that dreadful groggy feeling when you wake. A stroll in the shade is better though - studies show that students feel more energised and positive after bright light compared to a nap after lunch.

4/ Cool sanctuary - Leave bedroom curtains closed during the day to keep it cool and bring the temperature down before you turn in for the night. That will reduce the need to run energy-hungry fans and air-con units and make a big difference to quality and quantity of sleep too. It makes sense when you realise that we evolved to rest at night when the temperature falls. That cool, dark space will be even more inviting when it’s time to turn for the night.

5/ Power down - Cut the light levels right down at least two hours before bed, even if it’s still light outside. These long summer days don’t give our brains that wind-down time they need. It takes around two hours for the alerting effects of light to wear off so that levels of the sleep hormone, melatonin, can rise and carry us into that deep sleep we so desperately need. 

6/ Make sure it’s dark in your room - doubly important when it's still daylight outside. Your eyes are responding to light even through closed eyelids (put your hands over your eyes now and you'll see what I mean). If you can see across the room, it’s bright enough to stop your brain going into deep sleep - and increases your risk of heart disease, diabetes and depression.  So use black-out blinds or eye patches. If you leave the windows open to catch any breeze that’s going, it’s likely to be noisier in your room. So use ear plugs to help your busy brain to switch off too.


Oh and don't forget to enjoy it - the days are already getting shorter - we'll be complaining about the dark evenings soon!


 - Hue-Heat Hypothesis: A Step forward for a Holistic Approach to IEQ,  Read more...


International Day of the Moon- light pollution and the marine environment

– The spectral and spatial distribution of light pollution in the waters of the northern Gulf of Aqaba (Eilat)


Adults with ADHD and photophobia

 - High Prevalence of Self-Reported Photophobia in Adult ADHD


ADHD and colour vision- Visual function and color vision in adults with Attention-Deficit/Hyperactivity Disorder



Light and calorie consumption. - Shining Light on Atmospherics: How Ambient Light Influences Food Choices