hopefully others can give you suggestions re; sweating, my husband tried in the early heat of kentucky june/july and gave up, it was far too difficult with the'burning sensation. There is aoptune device support group and there is a hat with a fan that others have used. Unfortunately my husband became so fatigued with his first rounds of treatment that combined with the confinement of 18 hours just didn't work for him, however, others seem to have more positive results. it is definitely a life style change, so keep communication with the optune team and support group. I dkn how active your md is , ours just had referred us to the optune team and felt they were best aware of how to answer questions. be aware however that they are not medical personnel on the 24hour help line but technicians. The trainer is not a nurse, but a patient care tech ours was very helpful with dos , don'ts sharing other pt experiences. good luck My husband is however now 4 months over the expected prognosis of a year to live, but has for the last 6 months been confined to w/c to chair, due to poor mobility and balance. unfortuntely for him it was clear from the beginning that a biopsy would have disabled him more and thus he was considered inoperable, hopefully yours has a better description of the tumor that has better chance of targeted treatment. ours didnot.

My husband was diagnosed with GBM in April 2024. He also has done the surgery, radiation and Temodar. He has worn the Optune devise for around 9 months. Like your husband, he was in excellent shape (daily long distance runner). He is unable to run now, but can still go for walks without using his walker. The Optune beeps 5 times when out in the sun, has to be reset in the shade and is annoying. But he has never been shocked from the device. We found that a cooling hat helps (like golfers often wear).
So far MRI's have been good. The only major problem we have had with Optune is that sore spots have started to develop under the arrays on the top of his head. Several weeks ago, some of the spots bled and were pretty bad. Optune staff can not give medical advise. We have kept the sores clean, stopped wearing the device for 4 days to allow healing. I've been able to reposition the arrays and cut off some of the adhesive bandage to avoid the spots. Our radiologist who prescribed the Optune said it was OK to place the arrays a little different than the prescribed photos. All is well now.
Wishing you the best. Hang in there.