Should I?Reviewed: 2024-06-10~1 min

Should I Drink Water Left in a Hot Car? Evaluating Water Safety after Extended Sun Exposure

Short answer

⚠️Depends / use caution

It depends—drinking water kept in a sealed plastic bottle inside a closed car under direct sunlight for several hours is generally not recommended, especially if you are pregnant.

Why people ask this

People wonder about drinking water left in a hot parked car at shopping malls, particularly in the summer when inside temperatures can soar. Pregnant individuals may worry about extra risks from chemical leaching or potential bacterial growth if a bottle sits in 95°F heat with closed windows for 4 hours or more.

When it might be safe

If the bottle was factory-sealed before being placed in the car and is still tightly sealed when opened
If the bottle does not appear warped, discolored, or damaged from the heat
If you are unable to access other sources of clean water and must hydrate urgently

When it is not safe

If the bottle was previously opened or partially consumed before being left in the car
If you notice any changes in taste, smell, or appearance of the water or bottle
If the plastic bottle is noticeably softened, warped, or has an odd odor
If you feel unwell after drinking, such as nausea or digestive upset, seek medical advice—especially during pregnancy

Possible risks

Heat can cause certain chemicals (like BPA or antimony) to leach from some plastics into the water, potentially posing health risks—especially for pregnant people
Bacterial growth is more likely in partially consumed bottles left in a warm, closed car
Drinking compromised water may result in mild digestive upset or nausea
Vulnerable individuals (such as those who are pregnant) may be more sensitive to chemical exposure

Safer alternatives

Use an insulated stainless steel water bottle to reduce temperature changes and chemical leaching
Bring water with you instead of leaving it in the car for extended periods, especially on hot days
Choose single-use water bottles only when you can keep them out of direct sunlight and away from heat
Store water in a cool, shaded place if you need to leave it in your vehicle for any length of time

Bottom line

If you're pregnant, it's safest to avoid drinking water left in a hot, sealed car for hours—choose water that has been stored in a cooler or an insulated container when possible.