Some of the more adventurous citizens are undergoing voluntary amputations to gain prosthetic arms and legs, boosting strength and endurance by orders of magnitude. There is even artificial skin based on nanotechnology, which can be used to give the appearance of natural skin when applied to metallic limbs.
These various upgrades have become available in a series of gradual, incremental steps over preceding decades, such that today, they are pretty much taken for granted. They are now utilised by a wide sector of society – with even those in developing countries now having access to some of the available upgrades due to exponential trends in price performance.