I tried this out recently because I was curious to find out if I can survive one.
Also because I thought it would be wasteful to pay for a hotel room when you have to check out by 4 am and leave for the airport ( I won't be able to sleep anyway due to anxiety). And you have to pay surcharge for taxi fare. And I didn't want to trouble anyone to wake up early just to send me to LCCT.
So, survive I did.
I slept for just 75 minutes, nodding off sideways with my head rested on my backpack. There was no sleep-friendly place or spot in LCCT-KLIA. Why ah? The airport authorities probably discourage it. A few Dutch girls were chatting rather noisily up till 1 am. Others had their sleeping bags and made themselves comfortable on the floor and dozed away. Waiting chairs were pulled together to form some kind of sleeping 'bed'. Some, like me, were wide awake and registered blank expressions, just looking, not seeing.
It was bloody cold. Freezing past midnight. And the overhead lights were too bright. I pulled my hoodie over my eyes and wrapped myself tight in a spare shawl.
After numerous re-attempts to catch my forty winks I gave up and walked around every now and then. The place started to stir for the early morning flights at about 3:30 am. I got some coffee and half boiled eggs for a very early breakfast. Finished my novel. Walked the entire length of LCCT and observed travellers and workers alike.
These are KKIA pics, by the way. Didn't take any pics at LCCT.
If you ever plan to sleep at the airport, make sure you make some preparations.
It gets bloody cold; so bundle up. Wear covered shoes, otherwise put on socks.
Stake your spot as early as you can. Other travellers planning to stay overnight will also scout for the 'best spot' a.k.a. a corner with the dimmest lighting, away from pathway traffic, not too near to the washrooms.
May be a good idea to invest in those inflatable travel pillows, eye masks/shades and ear plugs.
Have a good book. Might come handy if you suffer 'insomnia'.
Ipod, or handphone with earphones.
Some snacks or sweets, in case you're feeling peckish. Some water.
Leave your bulky bags at the Left Luggage Counter. Otherwise you need to lug them along everytime you need to go to the washroom. Just have your hand luggage.
Oh, and before you doze off, make sure you set your alarm to wake you up in a few hours time. Try to wake up half an hour earlier so you can use the washroom to freshen up before it gets crowded.
On the other hand, if you really don't want to sleep while at the airport, have some coffee. A lot of coffee.
That should help :)