Fever and feeling cold 12 days post chemotherpay. What could be causes?

Evaluation. You should be evaluated and have blood test (CBC ,blood culture)to find the cause and to be treated.
The fever. is bothersome....get it checked out ASAP.....Your Oncologist should be On-Call or have someone On-Call during this Holiday weekend !!! Call NOW! Good luck Hope this helps! Dr Z.
Basic education on C. Anyone receiving Chemo is provided some basic education, smart tips to be followed by the patieint. One of these is fever which can be sign of infection requiring medical assessment and checking your CBC. I am surprised that you have had "Fever " for 12 days and are still seeking help from doctors who are far away from your location. Do you not have access to your Oncology Nurse or GP or oncologis.