SYDNEY is bracing for near-record December temperatures of up to 42C today as police launch a “heatwave action plan” amid warnings of health risks.

The Bureau of Meteorology expects temperatures in western Sydney will “nudge” the highest ever for the Christmas holiday month of 43.7C recorded at Richmond on December 21, 1994.

media_camera Sydney is set to swelter through extreme temperatures today. Picture: Peter Clark

Temperatures in the city are expected to be cooler, peaking at about 37C — short of the December record of 42.2C posted on December 20, 1957.

A bureau spokesman said a sea breeze due early in the afternoon should cool coastal temperatures, but the 40-degree heatwave would continue into tomorrow in the western suburbs.

The heatwave action plan urges people to take precautions in the “extreme” conditions leading up to the New Year’s Eve celebrations.

“If you can, it’s a good idea to spend some time in an air-conditioned building,” a NSW Police Force statement read.

“Everyone needs to take care in hot weather but some people are at higher risk of heat illness, especially if they are older, live alone or are socially-isolated.”

Sydneysiders are urged to stay well hydrated, limit physical activity and avoid the sun during the hottest part of the day.

Everyone is also urged to be on the look out for signs of heat-related illness, including: confusion, dizziness, fainting, nausea, vomiting, weakness, headaches and sweating.

media_camera Sydneysiders are urged to take precautions in the lead up to New Years. Picture: Peter Clark

media_camera Health experts warn people to put on sunscreen, stay out of the sun and stay well hydrated. Picture: Mark Evans

Director of environmental health Dr Ben Scalley said people should minimise physical activity and spend time in an air-conditioned place. Transport for NSW advised against travelling during the hottest part parts of the day and to carry water.

For more information, visit the Beat the Heat website.