If you wait until your sheets start getting crunchy before you wash them, listen up. You need to wash your sheets once a week. Why? Sweat and skin particles build up on your sheets while you sleep, giving dust mites a lovely environment to live and breed. This can lead to allergy problems. Not only do you need to wash your sheets weekly to fend off these parasites, you also need to wash your sheet a certain way.
How to wash your sheets right
Extreme heat or extreme cold kills dust mites. Since putting your sheets in the freezer doesn't clean off the sweat and skin particles, you need to wash your sheets in hot water. The Mayo Clinic says to aim for 130 water that is at least 130 F (54.4 C) to kill dust mites and remove allergens.
Not sure how hot your wash water is? Check your hot water heater's settings. If your hot water heater doesn't show how hot the water is on the dial, there is a way to test your water. Turn on the hot water tap in your kitchen. Wait for the water to warm up, then fill a glass with it. Put a meat or candy thermometer into the water. Is the reading 130 F (54.4 C)? If not, you will want to raise the heat on your water heater.
Even better, if your washer has a sanitize setting, use that. This feature activates heaters in the washer that will heat the water hot enough to kill germs and parasites.
Dry right for a double-whammy of clean. Drying your sheets at high heat can kill anything that your washer missed. Dry your sheets for at least 15 minutes at 130 F (54.4 C).