A new Korean study showed that washing linens in a 140 F water killed nearly all dust mites, whereas warm (110F) or cold (86F) water eliminated only 10% or less of them.
For fabrics that can't tolerate hot water, use warm or cold but you will need at least 3 rinses to effectively remove dust mites.
And, since scents can aggravate allergies, use a fragrance free detergents like: All Free ($6.00 at grocery stores)
pop non-machine washable items like a stuffed animal into a ziploc bag and leave it in the freeze overnight.
The lack of humidity kills dust mites.
By Finest Linens and Things