On 20161210, I would have only less than three hours of sleep in 24 hrs. This challenge has prompted me to seriously learn how to sleep anywhere and anytime when we need to sleep.
Before that, I have faced many sleeping challenges. In Summer 2007, my sister and I slept at the Bangkok airport while waiting for a transit to Seoul. In Summer 2010, I suffered from fever as a result of crossing multiple time zones slower that I expected due to an emergency landing of our aircraft.
According to World Economic Forum, people with a C-to-G mutation in the DEC2 gene (a transcription factor), resulting in the Pro-to-Arg gene product, were born to need less sleep . Margaret Thatcher (19251013-20130408, who lived for almost 88 years old) could get by on only four hours’ sleep a night.
To sleep when necessary:
- relax + imagine + visualize ourselves asleep
- take power naps of 10-20 minutes
- block the light e.g. using an eye mask or a scarf of light material 
- try lying down
- dress for bed when flying
- lower the temperature
- reserve beds for sleep only, not work or study
- stay hydrated
- drink chamomile tea (a safe herb during breastfeeding)
- do not drink caffeine
- eat food high in Mg and vitamin B complex
- do not eat spicy food as it may cause heartburn
- do not take sleeping aids if possible
 A yellow oriental scarf that I bought in Beijing helped me to nap < 30 minutes at my work chair to endure long hours on 20161211 when most of my colleagues were not at work sites.
 One of the scientists involved in the Dec2 study is Ying-hui Fu, who suspected that her breast cancer was due to irregular sleep patterns!