Cheese is essentially the controlled decomposition of dairy. The rate of decomposition is a function of temperature, moisture, and salt.
Over 2000 years ago Roman legions
carted around wheels of Pecorino as rations for its high calorie density and long self life (years?).
As mentioned above, hard salty cheeses are great for backpacking. I've even taken semi hard cheeses like Emmental or Cheddar which is fine for several days, though I don't think I would go more than about 4 days with these unless the temps were relatively cool.
Like salted butter, it's probably fine to leave cheddar out at room temperature for a while. Let your eyes and your nose be your guide :)