My Husband Had A Option Treatment On July 2nd. It

My husband had a option treatment on July 2nd. It would be about his seventh. His cat scans showed significant improvement but yesterday he suddenly developed a fever that is followed by raking chills. Episodes last several hours , seems to subside but not completely go away and comes back . He has had 4 cycles since yesterday. No diarrhea or vomiting. We have tried to contact his care through his health portal but no reply since this morning. Do we need to be more proactive or can we wait. We haven’t heard of a virus in the area , south central Michigan. We can not take his temperature by mouth as he has had surgery that makes it complicated and do not have another accurate thermometer