[Vylen]

Fireworks shows at 10+ minutes should be ok, presumably you're taking videos of fireworks displays at night

Obviously the sensor would heat up faster when there's more light to capture - conversely, it should heat up slower when there's less light

[UnknownVT]

Pardon the little off topic -

I have the K-x and have not shot any video with it -
I use the K-x primarily as a stills camera.

For video I actually bought a HD pocket camcorder -
(the Flip is the most famous)
mainly because I can carry that more or less everywhere -
whereas even though the K-x is one of the most compact dSLR
it is big and cumbersome in comparison.

The models I have are the Kodak Zi8, and the waterproof and more rugged Kodak PlaySport Zx3 (note there is a brand new Zx5 - but early reviews are not good - so I would avoid the Zx5 for now).

Both can and will video to the battery's capacity limit about 1.5-1.75 hours without any ill-effects and store on SDHC cards up to 32Gb for about 10 hours at 720p/30fps.

ConsumerSearch.com on Compact HD Camcorders
claims to review the reviews -
ie: survey available reviews, rate them and come to some consensus -
what I'd logically do if I had the resources and time.

Their top pick was Kodak Playsport Zx3
worth considering is the Kodak Zi8 (their review)
I like this with the KODAK Zi8 Silicone Sleeve makes it more durable

Both these camcorders are actually capable of very good footage up to 1080p/30fps and 720p/60fps.

Their current pricings are
Zi8 ~$100 shipped (or $80 refurbished)
Zx3 ~$110 shipped (or $90 refurb)

Those seem stupidly cheap prices for what they are.

[RolloR]

if the mechanical shutter dies, then we have a full-time video camera? lol

I use the k-x for lots of video also. So far, it just shortens the lifespan of my Enerloops, especially when I frequently use the quick charger.

quick-drain + quick-charge is not very nice for rechargables.

It also fills up my hard disk.