Hamsters unlike cats, dogs etc. that can have injections to protect them from the outside and all the infections they can get, hamsters do not have an injection. There is also the risk of parasites such as mites etc. this can cause a big risk to your hamster if not treated straight away by a trained vet.
Hamsters are also prey animals and the noise and smells can stress out our little domesticated friends. Along with the many different temperatures all of these factors could have an impact on their health. Hamsters are also crepuscular creatures and will come out around dusk until dawn. They tend to be asleep in daylight and night would be a very risky time to take a hamster out. They also have sensitive
eye site and do not like bright areas.
There are ways a hamster can experience natural textures without them getting stressed outside. You could simply make a natural theme cage with herbs, coco fibre and safe grass.
Here some videos on ideas of what you can do!