The info I read earlier, was to not put things like our masks in plastic bags, as the virus would have a nice warm place to go forth and multiply!
For masks, they suggested a clean paper bag was a better storage location than plastic.
Thus for quilts, I would think the same concept ..... Launder in as hot as water as possible. Likewise, as hot as possible in the dryer.
Maybe the best advice for your Aunt would be to ask those treating her and giving her the medical advice as to the best procedures for her personal laundry and items such as her quilts.
Good health to your Aunt, yourself and your family.
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