Of the 96 people found dead of heatstroke this summer in Tokyo's 23 wards, 87 were aged 65 or older, the Tokyo Metropolitan Government said Thursday, urging the elderly to drink water and take salt before going to bed.

Many victims died at night in their sleep. Twenty-four died between 5 p.m. and 5 a.m., while 37 died between 5 a.m. to 5 p.m. The time of death of the remaining 35 was not known, the Tokyo Medical Examiner's Office said.

Of the 96, 92 died at home, the metro government said. In some cases, air conditioners were not used despite the high temperatures.

"You should drink some water before going to bed and when you wake up to go to the toilet at night. You should also keep your room cool," Masaru Nakaya, an official at the examiner's office, pointed out.

Of the 96 victims, 71 were living alone. The metro government urged relatives and neighbors to regularly contact the elderly in their community.