How to create a ‘fake’ sleep tipOne of the things that you realise as you learn more about sleep is that the advice we give to patients as ‘sleep tips’ really has not changed over the years. Indeed in all the years that I have been involved in sleep I aware of only one genuinely new sleep tip and that is the advice about blue light at night which is based on the discovery of a new photoreceptor in the eye by Prof. Russell Foster and his team in 1991. (However this tip is actually just a different reason for the pre-existing advice recommending avoiding using screens before bed because they cause cognitive arousal). There are a myriad of other ‘new’ sleep tips out there, but for the most part they are nonsense.However given the hot weather one interesting tip has seemingly become part of the orthodoxy and that is the idea of putting your sheets in the refrigerator for a period of time to help you to cool down at night. I first heard this piece of advice about 10 years or so ago when a caller in a radio phone in mentioned that the dampened their sheets, put them in sealable plastic bags and left them in the fridge whilst they went to work and then used them to make up their bed. I thought that this was a bit of a silly idea but did use the tip in other interviews but always in an “and some people even...” or “the daftest idea I have heard “ kind of way. The first example on the web that I can find is of it actually being given as advice is from 2011 (here) and there were a few other mentions over the next couple of years (a variation of cooling your pillow in this way was suggested by Dr Chris Idzikowski in 2013 here). I am finally quoted in print in 2014 (here), however note that I am pretty dismissive of the idea “The effect of such methods is only very temporary,’ says Dr Stanley, ‘as our bodies quickly warm up the sheets and pillow cases.”However this year there has been a multitude of people actually giving this advice or variations of it as though it were an actual serious piece of advice . It is worth looking at some of them in detail. One advises to put your sheets in the fridge or freezer for 10 minutes (here), well to see how effective this would be you can do a simple experiment get two clean, dry cotton handkerchiefs and put one in the fridge and the other in the freezer wait 10 minutes and see how cold they are. The simple answer they are exactly the same temperature as when you put them in, the result is hardly going to be better with sheets which are much bigger. This recommends putting your sheets in the fridge for 1 hour (here) but the result will be pretty much the same. This one simply advises putting them “in the fridge or freezer before bed” (here).Of course the original advice was based on dampening the sheets first, which would make a large difference to how much they would cool (of course this would also mitigate against putting them in the freezer) however even if this did work there is another problem with this idea which is best illustrated by this advice, from a ‘sleep expert’ no less, “Pop your sheets, pillow cases and duvet cover in a plastic bag and stick them in the freezer 30 minutes or so before you go to bed. They’ll stay cool for a short while – hopefully long enough for you to get to sleep” (notice the use of the word “hopefully”). Surely the effort of completely making the bed on a hot night is going to raise your body temperature negating any benefit you might get from cold bed linen.This advice is whatever form is palpable nonsense however it is interesting how in a few short years such obvious mumbo-jumbo has for some, including so-called ‘sleep experts’, become an actual serious piece of advice.