I am not a camera expert and hopefully someone who is will answer, but I always understood sudden extremes of temperature were bad for cameras because you get condensation on the lens - I would think that an ice pack would create this sort of condensation, whereas just being on the beach probably wouldn't. Couldn't you bury it in your bag so it doesn't get direct sun on it?

Lavandula

I always just toss in a disposable camera instead, for quick snapshots on those kind of days.

I've never heard of putting a camera on ice, but what do I know?

Your instruction book will tell you the range of temperatures your camera can comfortably withstand.

I think an icepack could possibly do more harm than good. Camera batteries do not like cold.

You could take it out of the bag and keep it in the shade, since camera bags tend to be black and get hot, but bear in mind that sand is a big enemy of any camera, so be very careful with it.