NSW Health is reminding people to take precautions to protect their health as early season hot weather and heatwave conditions are forecast for parts of NSW this weekend and early next week.

NSW Health's Executive Director of Health Protection, Dr Jeremy McAnulty, said people should minimise heat exposure with maximum temperatures in the mid to high 30's forecast for many regions of the state.

Dr McAnulty said areas of the South Coast are expected to experience heatwave conditions commencing on Sunday, which occurs when there are abnormally warm days and nights for three or more days.

"Hot weather conditions will see temperatures up to 10 degrees Celsius above usual for this time of year in parts of the state, and NSW Health encourages people to take care of themselves and those who may be more vulnerable this weekend," Dr McAnulty said.

"Simple precautions can reduce the risk of heat-related illness. It's important you do not allow yourself to become too hot or dehydrated by minimising physical activity outdoors during the day and staying well hydrated by drinking water. Don't wait until you're thirsty before drinking water.

"It's best to try and avoid the heat of the day by staying indoors and keeping curtains and blinds shut early. If you don't have air conditioning, using a fan, wetting your skin with a sponge, spray or water-soaked towel can help to keep you cool.

"If it's hard to keep yourself cool at home, you should also consider spending the day at cooler places, like the shopping centre or an air-conditioned community venue.

"People over 65, people with chronic medical conditions and babies and young children are particularly sensitive to the heat. Stay in regular contact with elderly neighbours, friends and relatives who may need help."

Heat exposure can cause severe illness, hospital admission and even death. Heat can worsen the risk of underlying health conditions and cause a severe medical episode such as a heart attack or difficulty breathing.

Signs of heat-related illness include dizziness, tiredness, irritability, excessive thirst, fainting, headache, changes in skin colour, rapid pulse, shallow breathing, nausea, vomiting and confusion.

People showing signs of severe heat-related illness should cool down immediately by taking a cold shower or bath if possible, or by fully wetting the skin with water while lying in the shade, and seek urgent medical attention. In an emergency, call Triple Zero (000).

Dr McAnulty advised that with Sydney and other parts of NSW experiencing poor air quality due to hazard reduction burns, people are encouraged to check the air quality levels where they live and the health activity guide.

More information on how you can protect yourself from heat can be found online at Heat is a health risk - beat the heat