Do you know what to do in these emergencies?

If you're at the beach and a child gets in trouble in the water or someone collapses near you, would you freeze or would you know exactly what to do?

St John's Three Steps for Life delivery lead Mia Noyes shares life-saving actions for when the unexpected happens — from allergic reactions and cardiac arrest to choking and drowning.

A person can have an allergic reaction from various things like food, medication, venom or chemicals.

What to look for: Swelling, a rash, nausea, dizziness, diarrhoea, or trouble breathing.

Help them to take their allergy medication – if they have one. If they don’t improve, use an EpiPen (or you can administer it for them) and call 111 for an ambulance. Or if you are unsure, call the 0800 Healthline.

If you get a bee sting, first remove the stinger with tweezers, your fingernails or scrape over it using a plastic card from your wallet.

How to use an EpiPen: Pull off the safety release at the top. Stab the pen into the thigh for three seconds then remove and set aside.

ProCare clinical director Allan Moffitt says the two conditions differ – heat exhaustion is dehydration through excessive sweating, while heat stroke is overheating. Both can lead to unconsciousness and cardiac arrest if untreated.

What to look for: Sweating, agitation, feeling thirsty and dehydrated.

What to do: If someone's overheating, move them to a shaded spot, loosen or remove clothing on their chest, fan them, and get them water. Dr Moffitt warns against ice baths as they trap heat in the skin. Instead, wipe them down with a wet towel and let the water evaporate off the skin.

For heat exhaustion, Dr Moffitt recommends drinking electrolytes because the body absorbs them quicker than water.

If they become unconscious, call an ambulance.

A cardiac arrest is when the heart stops beating.

A person having a cardiac arrest will:

What to do: Call an ambulance. The call handler will guide you. If they confirm it’s a cardiac arrest, they’ll ask you to start CPR.

Place your hands in the centre of the chest (one over the other and lining your wrist with their nose), keep arms straight, and push hard and fast — 30 compressions. If you are comfortable doing rescue breaths, blow two mouth-to-mouth breaths while pinching their nose after every 30 pushes.

Dr Moffitt says the chances of CPR success increases with a defibrillator. The AED Locations app locates the nearest Automatic External Defibrillator to your current location.

Defibrillators contain instructions and sometimes come with a speaker that communicate the steps for you.

For infants: If a baby becomes unresponsive and stops breathing normally, call 111.

Lay them flat on a firm surface, clear the airway if possible with your pinky finger, and check for breathing. If there’s one breath or none in 10 seconds, use your thumbs in the centre of their chest to do 30 compressions, followed by two gentle breaths (covering their nose and mouth with yours). Then repeat.

Surf Life Saving coastal safety manager Tom Kearney says it's crucial to swim between the red and yellow flags at patrolled beaches.

If you see someone in trouble, call 111 and ask for police. They’ll connect with lifeguards and Coastguard right away.

If you can, throw or get a flotation device to the person — a life jacket, chilly bin, rugby ball or one of the public rescue tubes at beaches. You need a floatation device for you and the person in trouble.

"If you can't swim, obviously don't get in the water with that bit of equipment," Kearney says.

"Attach the equipment to yourself, swim out to that patient, create some space between you and that patient, and make sure you're putting that flotation in between you and the patient. Make sure they hold on to the flotation, calm them down, and then essentially wait until further help arrives."

Trying to pull someone back to shore instead of waiting can put you both in danger, he says.

Once the person's back on shore, check if they're responsive. If emergency services haven't arrived and the patient is not breathing normally, roll them briefly onto their side to let water drain, then start CPR. Keep going until help arrives.

Check if someone is choking by asking. If they are, they won't be able to respond by voice or cough. Call 111 for an ambulance.

What to do: Start with five firm back blows between the shoulder blades. If that doesn't work, do five chest thrusts: wrap your arms around them from behind, make a fist in the middle of their chest, and pull sharply inwards. Alternate between the two until the blockage clears.

If the person is taller than you, ask them to lean over a chair so you can deliver the blows.

If the person becomes unresponsive, start CPR.

For babies, call an ambulance immediately. If the baby is limp or not breathing, support their head, turn them over and give five back blows between the should blades using the bottom of your palm.

Check after each one. If nothing comes out, turn them face up and give five chest thrusts using your thumbs in the middle of the chest. Keep alternating until the object comes out — or start CPR if they go unresponsive.

Dr Moffitt says significant injuries on the beach - say from a stingray barb - may require a clinic visit, if you can't control the bleeding. (Also see St John's guide on insect and jellyfish bites.)

But if it's a minor shell cut, for example, wash out the sand using soapy water or an antiseptic solution then dry and cover the wound. If infection is a worry, use an antiseptic cream, he says.

"Keeping it covered makes it heal quicker, and it stops bugs from getting into it or dirt."