I had a maths teacher, a very sweet woman, but utterly unable to control the class.
Anyway she was an otherwise very clean lady but she obviously had a medical issue with excessive under arm perspiration. And to make it worse she had a fondness for silk shirts, which is absolutely the worst thing to wear if you sweat a lot since you would see huge wet stains under arm. Poor lady, the other kids would make the nastiest comments which I hated. The worst thing was the more cruel they were, the more upset she got and the more she perspired.
In the chemist they sold (and still do) a super strong antiperspirant deodorant for people with this problem and I tried to get up courage to tell her about it but always chickened out in the end.
Most people who smell to the point others are offended almost certainly suffer with depression.