LifeVest causing skin irritation from fabric… what helped?

My dad recently started wearing a ZOLL LifeVest 24/7 and is getting redness/itching where the fabric rubs against his skin. It’s NOT under the electrodes or therapy pads, just the fabric-contact areas.
Has anyone dealt with this? What did you safely use for relief or prevention…moisturizer, hydrocortisone, anti-chafing cream, powder, etc.? Did adjusting the fit or getting another garment help?
Would really appreciate recommendations from anyone who has worn a LifeVest or cared for someone who has.