Can inmates get an extra blanket if they are cold?

Inmates are supplied with the essentials which include bedding and one blanket. This is not a hotel, this is a prison. They cannot call housekeeping and get another pillow or blanket. The only way is to barter for one with another inmate - there is always an inmate in every facility that is very plugged in and somehow has access to all kinds of contraband (for a fee). This scenario is a real possibility.

My first week in federal prison, I was forced to start out in the SHU, solitary confinement, in the cell 24/7. One morning, when the CO brought my breakfast, it came with coffee. When the CO came back around to my cell door, he asked if everything was ok, "did i need anything".

I responded, "Yes, may i have another coffee?" 

He responded, "From Starbucks or Dunkin Donuts?" and laughed very loudly. Needless to say, I didn't get that second cup and I never asked again.