There is nothing better than the feeling of clean bed sheets to greet us ahead of a good night's sleep.
In reality, they are a real pain to wash and dry - we are all probably a little guilty of keeping dirty sheets on the bed long beyond their welcome.
However, the hygiene and medical ramifications of this grubby little habit are quite disturbing.
Fungus simply loves dirty bed sheets, especially when it is hot and humid outside.
Even when the climate isn't warm, humans still produce 26 gallons of sweat in bed each year leading to what some Research Gatecalls an 'ideal fungal culture medium.'
Pillows, for instance, are a prime breeding ground for these little critters.
A recent study found that a sample of feather and synthetic pillows between the 1.5 to 20-years-old could contain 16 species of fungus.
If that wasn't grim enough fungi and bacteria can emanate from your sweat, skin cells, saliva, mucus and excretions as well as from foreign materials that you share you bed with like lint, dust, dirt, faeces and animal cells.
All these elements can start to have a significant effect on your health within the space of a week and could cause allergic reactions like sneezing and sniffing, as you are basically breathing in all this nastiness when you are in the land of nod.
These would be even worse for someone suffering from asthma or significant allergies, leaving even the most immune person with a scratchy throat.
We hear you cry:
What can we do to stop this?
Well, New York University microbiologist Phillip Tierno is here to help.
When speaking to Business Insider, Tierno recommended that bed sheets should be cleaned once a week.
If you touched dog poo in the street, you'd want to wash your hands.
Consider that analogous to your bedding.
If you saw what was there — but of course you don't see it — after a while you have to say to yourself, 'Do I want to sleep in that?'
He's got a point.
If you were thinking of getting some lighter sheets or sleeping next to the window to stop yourself from sweating so much, that is unlikely to help either, as you can't prevent gravity.