Is my dwarf hamster dying??

Since last night he is cool and stiff, still breathing but hardly moving.
Is he dying and will a vet visit help or is it better to leave him to pass away here,he doesn't appear to be in any pain,he was healthy until last night then he went funny all of a sudden.Any helpful suggestions as to what it might be.
Update: thanks for all the answers,he died last night.
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