If you need an ambulance, call 000.
Medical centres with general practicioners are available for minor ailments without an appointment around the city and suburbs. Expect to wait around an hour or so to see a doctor. Upfront charges are usually around $50 for a standard consultation, and most centres accept credit cards. Many medical centres remain open until 10PM or so, and a few remain open 24-hours. Those with an Australian Medicare card will find many medical centres in Sydney that "bulk-bill".
Most hospitals in Sydney have emergency departments, but check before attending as some do not. Those emergency departments are open 24-hours. See the Australia article for more details on health charges.
Many pharmacies stay open after normal business hours, often in proximity to medical centres, and there are a few that stay open 24-hours. You can call +61 2 9467 7100 to find the location of your closest after hours pharmacy.
public transport after dark
After 9PM, smaller outer suburban stations can be very quiet, and many are totally unstaffed after this time. The trains can also be empty when they get towards the end of the line at this time. Don't expect a taxi to be waiting at every station--only the major ones will have a well patronised taxi rank.
Travel in the carriage closest to the guard's compartment, which is marked with a blue light on the outside of the train. Drunk people are common on trains late at night, particularly on Friday and Saturday nights. If you ever feel concerned for your safety on any Cityrail train, you can call 1800 657 926 to speak with Cityrail security, then can sometimes arrange for a transit patrol to board the train and provide assistance. It is generally more advisable to seek assistance from the guard however as Transit Officers are few and far between. In more modern trains, you can press the button in the entry area to speak with the guard. Every train station has an orange emergency help point monitored by CCTV that connects to Cityrail security, usually towards the centre of the platform.
Nightride buses, which replace trains after midnight, can arrange for a taxi to meet you when you get off. Ask the driver.
beachgoing
If you are going to the beach, take the same precautions as you do anywhere in Australia. See Beach going.
The biggest thing to remember when swimming at any Sydney beach is swim between the yellow and red flags. These flags are places by the lifeguards and indicate the safest place to swim at the beach away from dangerous currents.
Sydney has no really dangerous jellyfish. Bluebottles Portugese Man-Of-War are blueish-purple stingers that hit the Sydney beaches a couple of days every summer, when the wind direction is right. They have an air-bladder that floats on the water, and stinging tenticles. Often the air-bladder can be no bigger than a coin. You will see the evidence of them with their air-bags washed up on the beach if they are present. They can give a painful sting - even when on the beach - but it won't keep everyone out of the water. Apply a heat pack if you can, or ice, or salt water. The best way to remove the pain is to run the affected area under the hottest water you can stand. Vinegar is useless. Sometimes small transparent jellyfish appear in the harbour and estuaries. You can usually avoid any groups of them, but they are mostly harmless. More rarely larger purple jellyfish are in the harbour and other estuaries. If you see these in the estuaries, best to stay out of their way. Probably more of an issue to water skiers than to swimmers.
Sydney ocean beaches all have shark mesh nets around 100 metres out to sea, and are regularly patrolled by air for sharks. A shark alarm will sound if any are sighted, and you should get out of the water. The risk of shark attack swimming on a patrolled beach between the flags is virtually nil. Shark attacks are rare on Sydney beaches, but they have occurred, although there have been no fatal attacks for 45 years. Advice is to avoid swimming in murky water after storms, or at dusk or at dawn, and to swim in the netted enclosures within the harbour and other estuaries.
other violent crime
There are few complete no-go areas in Sydney.
The Block on Eveleigh Street in Redfern, directly opposite Redfern station, is still to a certain extent an area demonstrating urban Aboriginal disadvantage. It is slowly being redeveloped, and the murals, vandalism, drugs and hopelessness being bulldozed. Common sense would tell you to avoid this area, unless you have a desire to see this side of Sydney, in which case take extra care.
Wooloomooloo, while gentrifying quickly, still attracts the bulk of Sydney's rough sleepers, and has large tracts of public housing. Avoid walking through parks or other sleeping places, and stick to main roads. Muggings and assaults are not uncommon. If in doubt, catch a cab.
Some areas of South Western Sydney, like Campbelltown, Lakemba, Bankstown, Liverpool, Hoxton Park have a reputation. Though they are generally safe during the day these are largely faceless 1960s/70s dormitory-style suburbs, offering little of real interest to most visitors. If you do visit these areas, consider travelling with a Sydneysider.
Be careful in the red light area of Kings Cross at night. Although the main street in this area has been cleaned up immeasurably by the police, crime does still occur and pickpocketing or mugging can happen to the unwary, especially in quiet laneways. Women should take extra care at bars and keep an alert companion at hand, especially in the central hostel area, and take precautions against spiked drinks.
When using train services at night take precautions as most railway stations in Western Sydney are hotspots for assaults and robberies. Youth gangs may also be present in areas nearby most Western Sydney railway stations particularly on Friday and Saturday nights, it is wise to not approach or provoke as it will always tend to lead to misadventure.
alcohol-fuelled violence
Take care walking around George Street, The Rocks or Oxford Street especially on Friday and Saturday nights as there are many drunk people around who can get into fights. Usually fights with drunks are not completely random, and start with some sort of engagement. Avoid trouble, and don't hesitate to call police if you feel threatened.
Cope
United States
This Consulate takes an interesting approach to the security problems plaguing the US. You first pass through a security screening on one floor where your electronic gadgets are confiscated for the duration of your stay and then you are escorted to the real consulate in their private elevator. That's where the real waiting begins. Make sure to use the facilities BEFORE going through security as there are none in the Consulate itself. There are shops in the malls below offering passport photos and a post office where you can buy pre-paid, tracked, envelopes. Oh, and don't even try to get in the door without making an appointment over the phone prior to arriving!