对于救人，特别是这次四川灾区有一种黄金72小时准则，就是救人必需赶在黄金72小时之内．这72小时是寸金寸光阴，快一分钟就可以多救一个人。这跟人的身体有关，人可以72小时不吃饭但是绝对不可以72小时不喝水．但是一但发生巨大的自然灾害，纯净的水源都会受污染．这时候干净的水就是个大问题了。 

The Lifesaver is a water bottle–but not just any water bottle. Through "an advanced ultra-filtration membrane that incorporates a high specification carbon block" it can convert dirty water to clean in a matter of seconds–you put in the water, pump it through the filter a few times, then drink. The cartridge is supposed to be able to filter out waterborne pathogens and eliminate bad tastes and odors, too. The replaceable cartridge has a filtering capacity of 4,000 to 6,000 litres, so it’s not short-lived: 700 litres is a year’s supply of water for one person. The military is interested, naturally, but an even more important application would be to supply clean drinking water after disasters such as the Boxing Day tsunami in 2004 or Hurricane Katrina: instead of distributing bottled water, you could distribute bottles that clean the water that’s at hand. And even in the absence of disasters, access to clean water is a worldwide problem. Hmmm. My daughter’s water bottle is starting to smell funny. Maybe I should be getting her one of these… Or maybe the Lifestraw is the way to go. It’s a plastic pipe filter 25 centimetres long and 29 millimetres in diameter that costs just a few dollars and can purify up to 700 litres of water.A word of advice, though: when giving a Lifestraw to a suffering disaster victim, find a different way to instruct him in its use than telling him to "suck it up."