​NSW Health is reminding people to watch out for snakes and spiders outdoors as the weather heats up during the summer holidays.

NSW Poisons Information Centre Senior Specialist, Genevieve Adamo said people should make themselves aware of what to do if they are bitten by a snake.

"Snake season peaks in late December and January," Mrs Adamo said.

"Australia has some of the most venomous snakes in the world, so it's important people seek immediate medical assistance for all suspected bites."

Symptoms from a venomous bite can include nausea, vomiting and a headache.

"If someone is bitten by a snake you should keep them still, call an ambulance and apply a pressure immobilisation bandage. Tight tourniquets should not be applied and the bite site should not be washed, cut or sucked."

Each Local Health District manages supplies of antivenom for the local hospitals, according to location and snake and spider populations.

Spiders are also a concern during the summer months, with funnel webs found in gardens mostly around the Sydney basin, Blue Mountains, Hunter region, Central Coast and South Coast.

Mrs Adamo said a bite from a funnel web spider is a medical emergency, which causes severe pain, sweating, vomiting, difficulty breathing and muscle twitching.

"A person should be kept still, while you apply a pressure immobilisation bandage around the bite and a bandage to the entire limb. An ambulance should also be called immediately and the patient taken to the nearest hospital for treatment," Mrs Adamo said.

A redback spider bite may result in pain and redness, but it is not considered life threatening. People should wash the area and call the Poisons Information Centre on 13 11 26.

For further information visit NSW Poisons Information Centre.

Vision and audio available for download: Watch Genevieve Adamo: NSW Poisons Information Centre Senior Specialist