There are two messages for race-goers heading to Addington today - don’t drink too much and watch out for the sun.

It’s the annual Christchurch Cup, and as in the past, thousands of punters are expected to be in attendance.

But, Christchurch St John are warning people to be careful in the sun with the mercury being tipped to hit the high twenties today.

St John Ambulance territory manager Kerry Mitchell said they'll have staff ready and waiting, but people need to remember the basics.

Mitchell said there’s twelve emergency ambulance staff at the races as well as two extra ambulances to support any issues that may arise in the city.

“So we have front line staff spread throughout to provide assistance for your trips and falls to your faints and collapses,” he said.

Mitchell is also asking people to “hydrate, hydrate, hydrate.”

He said that water, and food, will help keep people energised and will better enable them to deal with the amount of alcohol they consume.