Energy-efficient washers are designed to clean in water that is cold or warm, saving the consumer money. The Department of Energy even recommends using cold water to do your laundry whenever possible.
But, as CNN reports, studies have found the temperature needed for effectively killing possibly pathogenic bacteria is 140 degrees F or higher, which is considered hot water. As we've become more environmentally conscious, however, we've lowered the temperature of the water to save energy (and money). In Europe, for example, colored laundry is usually washed at temperatures between 86 and 104 degrees. In China, South Korea and Japan, cold water is preferred.
"When you do your towels with a cold water wash it's hard to get them really clean because they're so thick," Dr. Charles Gerba, a microbiology professor at the University of Arizona, told CNN. "You've got to use hot water wash and dry it really well."
If you don't, he said, "you'll get more E-coli on your face when you dry it with a towel than if you stuck your head in a toilet and flushed."
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