By contributing to the creation of an Earthlike environment for the wearer, every feature of a space suit can be regarded as a safety feature. Space suits are mainly designed to protect wearers from temperature extremes and impact hazards.
In order to keep astronauts safe from micrometeor impacts, space suits are built with multiple layers of Dacron or Kevlar. Interestingly, the main temperature hazard for an astronaut comes from the build-up of body heat within the suit. To counter the threat of dehydration and heat exhaustion, space suits are covered in a reflective material and equipped with circulating-water cooling systems.