Sweating during summer nights makes sheets inevitably damp. How often should we change them? Experts warn that failing to wash sheets frequently allows fungi and mites to multiply, leading to allergies and poor sleep. They identify 5 factors determining wash frequency and share the correct washing method.
Unwashed Summer Sheets Breed Mites
According to Good Housekeeping, University of Leicester microbiologist Dr. Primrose Freestone explains that oils, sweat, and millions of bacteria and fungi (like Staphylococcus, Corynebacteria, and even E. coli) shed during sleep cause sheets to develop odors. Bacteria break down sweat and body fluids deposited on sheets and pillows, converting them into odorous metabolic waste. If fluids and dead skin cells accumulate excessively, bacteria thrive in the damp environment, producing more odors. Sheets can also fade, feel sticky, and become uncomfortable.
Freestone adds that residues aren't always from our bodies – cosmetics, lotions, creams, and perfumes may also be left on bedding. All these substances encourage bacterial growth, a process accelerated by heat and sweat. The warmer the bed, the faster bacteria multiply. Fungi, mites, and dust mites feed on sweat and dead skin cells, potentially irritating the skin and lungs, affecting sleep quality. Dust mite feces can also trigger allergies. This is particularly severe in summer due to increased sweating.
5 Factors Determining How Often to Wash Sheets
Good Housekeeping recommends washing sheets every 3-4 days when nighttime temperatures are in the 20s°C, or at least once a week. The following factors influence wash frequency – the warmer the room, the more often bedding needs cleaning:
- Room temperature: Warmer rooms mean more sweating and more bacteria on the bed.
- Bedding breathability: Less breathable fabrics require more frequent washing.
- Sharing the bed: Sharing raises the temperature, requiring more frequent cleaning.
- Allergies: If you have allergies, wash bedding weekly.
- Pets: If you have pets, wash bedding every 3-4 days.
How to Wash Sheets Correctly
Good Housekeeping advises washing sheets in water at 60°C to kill bacteria and dust mites. If possible, use a biological detergent containing enzymes for optimal cleaning. If the care label doesn't allow such high water temperatures, use a dryer on high heat for 30-40 minutes to achieve similar results. If neither method is suitable, use a laundry disinfectant.
Mike Handlesman, CEO of FoamOrder and bedding expert, says keeping sheets clean also means keeping the mattress clean. Many think only sheets need washing, but mattresses, pillowcases, and duvets also require regular cleaning. Moisture and liquids can transfer to the mattress and foam layers; once penetrated, they're hard to remove. Using a washable mattress protector or simply airing the bed by lifting the duvet each morning helps reduce moisture accumulation and remove residual dampness.
Source: Good Housekeeping
