hot enough to fully disinfect fabrics.
The washing machine is completely overloaded: Stuffing too many items into the tub reduces water circulation and stops the detergent from reaching every fiber, meaning the towels will not get fully cleaned.
The bottom line is quite simple. With the right machine settings, including hot water, a good laundry sanitizer, and high-heat drying, mixing your towels is perfectly fine. Without those specific settings, you run the risk of potentially spreading bacteria from your kitchen kitchen directly to your face.
Understanding the Germ Factor