Human heads frozen in liquid nitrogen for future resuscitation; brainless full-body clones grown for cannibalization of parts: these are only two of the unintentionally nightmarish images that leading cryobiologist Segall (aided by science-writer Kahn, Beyond the Helix, 1985) conjures up in this fascinating, messianic, and downright chilling look at biotechnology's encroachment on aging and death. Given the freeze-dried-people movement's recent bad press--e.g., the arrest of leading cryonicist Saul Kent (Segall's mentor), who cut off and iced his ailing mom's head--it's no wonder that Segall devotes many pages to debating the numerous objections to the more outrâ€š aspects of ""life extension."" Despite his assurance that ""Rabbis have presided over frozen funeral capsules,"" however, most readers will likely shiver as they read through his autobiographical, self-promoting (lots of plugs for his Trans Time people-freezing company here), ecstatic rundown on recent and predicted life-extension breakthroughs. It's not just that the pervasive true-believer's air--beginning with Segall's confession that he has ""spent his entire adult life. . .trying to answer two questions: Why do we grow old, and how can we stop it from happening?""--gives pause; it's also that his well-articulated and informative brief on developments--including aging-retardation through diet, low-temperature surgery, organ transplants, cloning, and cryonics--finally betrays a reductionist mind-set (""death is [not] something other than a loss of specific organization of physiochemical matter"") that renders humanity as little more than intelligent, lovable meat. An otherwise clear and compact round-up of high-tech wonders made forbidding--thanks to the author's fervid Brave New World embrace of life-extension at seemingly any cost.