Plunket is reminding people to keep children within arms' reach when they're at the beach, river or pool.
Last year, six children under the age of five drowned whilst unsupervised.
Plunket national advisor, child safety, Sue Campbell said it was important to keep children close to you when they were near water.
If you can't grab them, you can't save them, she said.
"They can move quickly, they can be attracted to the water and may not see it as a danger, but just something that's really enticing to get into and just sort of step in. They can disappear under water very fast and drown very silently.
"So the good thing is, if you're there to grab them and to have fun playing with them, there's a lot less risk of them drowning," she said.
Ms Campbell said it was also important that pool owners ensured pools were properly fenced and gates were kept closed.
Don't leave unattended children in cars
People are reminded not to leave their children in parked cars, even for a moment, particularly over the summer months.
Ms Campbell said in hot weather a car could heat up very quickly, and children got distressed and dehydrate in a short space of time.
She said if a parent or caregiver was getting out of the car, even for a short period of time, they should take their children with them.
"The really important thing is don't do it. If you think you're going to have to get out of the car and leave the children, don't do that, take them with you, even if it's only for a short period of time.
"We all know that with the best intentions in the world, what we think will be a two minute duck into a shop to get something, can take longer. We can be distracted and stop and do other things at the same time."
She said leaving the windows down was not an option, as the car would still get hot and it brought its own risks if someone wanted to get into the vehicle.
Use of child restraints
Anyone travelling with children over summer should have them in an approved child restraint, Ms Campbell said.
By law, all children have to be restrained in an appropriate child restraint until their seventh birthday.
"That's something that's right for their size, it's not okay just to let them use the seat-belt," she said.
Ideally children should stay in a booster seat longer than their seventh birthday, because they were too short to fit an adult seat-belt correctly.
Children need to be 148cm before they could fit an adult seatbelt.
"Anything that can get them towards that height is great. It's all about making sure that the lap belt is sitting down touching their thighs if they are not on a booster seat. And they can sit well back on the seat, not slumped down. And that diagonal belt is placed well across their shoulder, touching their body as it goes down."
The most common cause of accidental death among children under five year olds involves motor vehicles, followed by drowning and suffocation.
Watch out on driveways
Ms Campbell also warned of the dangers of driveways to children, particularly shared driveways and those directly accessed from the house.
Safekids Aotearoa figures show that each year about five children die as a result of driveway accidents and a further 26 need hospital care.
"In the summer it's a great time to have barbecues to have people around and more people moving around the property," Ms Campbell said.
"It's really important that there is a rule that nobody drives out, without an adult being out there, as well to make sure there are no littlies who can get on that driveway and get behind or in front of that vehicle and not be seen," she said.
Ms Campbell said the key message was that adults made sure there were no children on the driveway, before a car left a property.
For more information
For more information you can phone Plunketline on 0800 933 922.
Alternatively, the Skip website and app has tips for parents and games to play.