Camp/hideout to recover and prepare

I think it would be cool to be able set up camp in a mission, or hide in an abandoned building. Purpose of it would be to heal and treat major injuries, or if you have a mechanical limb, "install" it or repair it. You could also check your weapons and modify them. In total, a player should be forced to make a decision between recovering or continuing the mission, neither should be completely one sided imo.