Originally Posted by
robyng
It should be about 5:45 am in Tokyo now. Current temp is about 80! Why don't you wake up your friend at 7:30-8:00 am - and try what I suggested. FWIW - if your friend is suffering from heat fatigue - he is probably dehydrated a lot by now. My favorite "cure" for that is V-8 juice (which has lots of sodium). Don't know if it's available in Japan. But - if you can't find it - find something similar (in a place like a department store food basement). If your friend is suffering from dehydration - a lot of fluids - especially those with sodium - should perk him up. If your hotel doesn't have V-8 juice - see what kind of Bloody Mary mix it might have (a lot of those are heavy in sodium too).
I've never seen V8 juice in Japan (that doesn't mean that it doesn't exist, only that it's not conspicuous), but the Japanese go-to hot weather beverages are the canned soft drink called Pocari Sweat (like a slightly salty lemonade, available in convenience stores and vending machines all over) and mugicha (iced barley tea). Also look for shaved ice, which stores advertise with a blue and white banner with a big red kanji splashed across it. It comes in all sorts of flavors, but I like
mizore (mee-zo-reh), which is a diluted sweet syrup.
At this time of year, there's always a shrine or temple festival going on somewhere. Check the local English-language publications for listings, which always give you the nearest train or subway station. The festivals tend to go on into the night, so a workable pattern in the summer heat might be to concentrate on museums and shopping (i.e. air conditioned places) and boat rides (the one from Hama Rikyu to Asakusa is a popular one) during the day and attend festivals and other performances in the evenings.
Take a day trip to Nikko, which will get you into the countryside and the mountains, or to Kamakura, leaving early in the morning, so you can be on an air-conditioned train when the heat of the day hits. If you can afford it (about US$80 each way), a day trip to Nagano on the Shinkansen makes for a pleasant excursion. The street leading from the station to the main temple is very attractive, the temple is interesting, and the elevation is high enough to have some effect on the heat.
But first it sounds as if you need to go to an English-language bookstore (the Kinokuniya south of Shinjuku Station has a whole floor devoted to English books) and buy a guidebook to Tokyo and a street atlas. You can spend one evening reading those and the next week exploring on your own.
By the way, your friend's behavior sounds like the way I was when I had mononucleosis as a college student. If your friend is not physically ill in some way, then he may be struggling with depression or substance abuse. In any case, wanting to be awake for only six hours a day is NOT jet lag, which consists of being awake and sleepy for the normal amount of time but only at the "wrong" hours of the day.