In Australia, it's commonplace for lifeguards to wear tights on their arms and legs. Although this may be an odd choice of attire to go swimming in, it can help save their lives. This is because tights can help protect against the sting of the box jellyfish, which is the most poisonous animal on earth. The jellyfish's sting is only effective when contact is made with the skin and, over the years, lifeguards have learned that wearing tights prevents them enduring agonizing pain, severe vomiting or even death at the hands of these most lethal of sea creatures. Pic: Getty Images