This is the one of the recent 'forwards' i've received in my email. Have also heard similar info in the past, of plastic bottles and their relation to cancer.
"Ladies, below is some VERY important information!
For the men, please pass this important information on to your female friends.
This information was given to me by my husband and I
know all the ladies in my life should know and please forward it to all
the ladies in your life.
My husband has a friend whose mother recently got
diagnosed with breast cancer. The doctor told her women should not
drink bottled water that has been left in a car. The doctor said that
the heat and the plastic of the bottle have certain chemicals that can
lead to breast cancer. So please be careful and do not drink that
water bottle that has been left in a car and pass this on to all the
women in your life."