Pre-molt or sick?

My t sling was fine and active in his burrow this morning,then when I came home, he was in what looked like a slight death curl,all of his legs were kind of n shaped and his pedipalps were completely in,then he slowly turned around facing th top of his burrow and all his legs and pedipalps were normal,but he is VERY sluggish. Th temp in his container was 19 deg celciuss so I turned it up to 24. Th humidity is normal. He has attacked but not eaten for about a week. Can t"s go into premolt in a matter of hours? His last molt was 2-9-11

---------- Post added 10-26-2011 at 06:57 PM ----------

Update: he crawled normally up his Tunnel and had a drink from his water dish, I lifted th lid of his enclosure and quickly ran back down his burrow like he normally does. Maybe he was cold? Or it's still early stages of pre-molt?. I'm confused!.

What do you mean by n shape? We're any of the legs curled under its body or were they just scrunched up against it?

Uh,I guess scrunched up sort of,I offered him a silkworm and he kinda stabbed at it but it was as if to scare it off, he also collapsed his burrow and I could still c him in a little 'cave" at th bottom but can't c him now coz he's diggn th other way.