Antarctica is not your usual holiday destination. Any trip to Antarctica needs careful planning to ensure you stay safe if you are not part of an organised cruise/tour.
The first thing you should prepare for is extreme cold, particularly in spring/autumn and even more so in the winter (although few people venture to Antarctica in the winter). However, even in the summer the weather can be unpredictable and temperatures can drop suddenly. Ensure you clothing is tailored to suit the possible temperatures you could expect for the particular season of your visit.
Strangely it is possible to have warm sunny weather for brief intervals during the summer days and with all the white ice and snow reflecting the sun it is possible to get sunburned to remember to always protect your skin.
Wildlife, although abundant (penguins!) in some areas are unlikely to cause you too much trouble but do keep well away from seals and sea elephants that can become defensive if threatened or if you are in their territory. Seagulls and other birds can also unpredictable and aggressive, particularly if you are near their nests. Sharks can be found around the seas of Antarctica although swimming in the far south of the Southern Ocean is not a popular activity. The best advice is to stay well clear of all wildlife, as you will be visitors to their country, they should be treated with respect and left to carry on their normal lives.
Antarctica is covered by a very thick sheet of ice and snow, whilst the majority is frozen solid it can move in large flows creating crevasses and ice falls. If you intent to hike, ski or travel anywhere you should be professionally trained in how to spot potential ice problems (although annoyingly some are impossible to spot until you fall into them) and how to rescue yourself and others if someone should fall into a crevasse.
If you plan on travelling to Antarctica and undertaking activities ashore then you should ensure you are fully prepared and properly trained for the alien landscape you will find yourself in. Antarctica is a SERIOUS continent and well and truly at home in the ULTIMATE ZONE.