Mickey

Unfortunately I'm a repeat player in this game. As one who has been there and done that not only once but twice, my first advice is to make sure your husband gets a Thyroid (TSH) blood test asap if he does not have a pre cancer TSH test. As you can see from my signature line, I had the same numbers as your husband does.
This is NOT something to worry about but rather something that MAY matter to you both after TX is over since without a baseline to show what is "normal" for your husband, you will have a difficult time getting help IF its needed. It's not too late to get a blood test as the thyroid is not damaged immediately.
While my CCC doctors were top notch on Cancer, for related issues like Thyroid - "not so much". I was not only extremely tired but also froze for two years, even in summer, and kept a winter coat on in air conditioned places yet I was constantly told: "Your TSH levels are normal" and I did not ask for the actual numbers or test results. Turns out however there is controversy over what is the right TSH level with labs having a 5.5, a 4.5 even though endocrinologists who went to Medical school in the 21st Century consider 3.0 as the highest acceptable level. Before TX, I had a TSH of 1.6 and after TX it shot up to 4.3. Now that I am "on the pill", I am finally warm again. Plus my energy is back My TSH level is down to 1.73 after 9 months of thryoid pills
Finally, many many people have no thyroid issues at all, so this may not even apply to you but they take so many blood tests anyway for the chemo, it's worth the insurance of a TSH test.
Welcome to OCF - and so sorry you have to be here.
Charm