What Causes Hot Flushes While On Methotrexate?

I have ra taking methotrexate and hydroxqlouriquine. My crp islow 3.5 but my esr is 62.ism flushing when rushing and when hot in my office .can my esr cause it and how do I get it down.i had a flare up a week ago but going down now my joints are. Ok caught it early but the flushing is worrying me