The bang out of bottle makes a big difference.

For busy people on the go, the car often acts as a portable storage unit.

You suddenly remember the case of water sitting in the trunk.

a photo of a thermometer showing a hot temperature and a water bottle

Photo: Getty Images

Before you dive in, consider these risks.

According to theNational Institute of Environmental Health Sciences, BPA is found in some plastic water bottles.

Numbers 3 and 7 may contain some BPA in the plastic.

A bottle that has been opened and left in a hot car can grow harmful bacteria.

“Our mouth has its own oral microbiome filled with bacteria” says Jafferali.

Once your lips touch the bottle, bacteria is transferred from your mouth to the container.

The same holds true for a reusable bottle.

Once you crack the seal, drink from it immediately or throw it out.

Bacteria from the mouth can flourish in extremely hot temperatures.

On the other hand, a clean reusable aluminum or glass bottle may be a safe option.

“To minimize BPA exposure and risk, choose a glass water bottle,” says Lebovitz.

Although, Jafferali notes that glass water bottles aren’t the best option for accident-prone children.

If the bottle contains BPA or has been opened, it’s best to avoid it.

Opting for an insulated reusable water bottle is your best bet.

double-check to clean your bottle between uses.