Fraught international negotiations leave sleep at a premium for negotiators and talks do not come more fraught than ones on global climate change, especially if your side is one of the main protagonists.
So, a suitcase of caffeine might be advised as China's climate change negotiators pack their bags for the trip to the Mexican city of Cancun for the next round of talks on saving the planet later this month.
Su Wei , China's chief negotiator, says he managed fewer than four hours sleep a day during three weeks of intensive, and unsuccessful, talks at Copenhagen last year.
Long meetings arguing over myriad technical and legal points in search of an elusive breakthrough can be tough and frustrating. Consider the chasm between rich and poor countries and it's easy to see why life is extremely difficult for the more than 2,000 negotiators from nearly 180 countries.
For many, the talks have become a power struggle between the developing and the developed world.
'Climate change talks are essentially a struggle against the developed countries' attempt to deviate from basic international principles of justice and fairness and to sabotage the UN framework,' Dr Huang Huikang, the Foreign Ministry official who is co-chairman of the Chinese delegation team said. 'The fight will go on.'