A hedgehog *out in the open* in the day is in serious trouble and needs urgent help.
Always.
No exceptions.
Any size.
Any time.
Hedgehogs are nocturnal prey animals, they have no defences in the daytime, it's deadly dangerous for them.
They are designed to hunt at night, to navigate and catch insects in the dark, occupying a specific ecological niche.
They are not adapted to withstand high temperatures, and their shape means they would rapidly dehydrate during daylight hours.
They are nocturnal animals.
So they don't come out in the day simply because they're hungry, or lost, or disturbed, or to move nests, or for any other trivial reason.
They come out in the day because it's warmer than the night and they are feeling cold.
Deadly cold.
They're feeling cold because they're so sick they're starting to die, and hypothermia is a stage of dying. Blood has been redirected to the vital organs, keeping them alive as long as possible, leaving the limbs feeling cold.
If you see a hedgehog like this, out in the open, in the day time, no matter how 'well' he looks, it is an emergency.
Please take them to a rescue (never a vet) URGENTLY.
ALT A hedgehog out in the day, in the open, is in urgent need of treatment from a rescue (never a vet).