Employment subject to be medically fit

One of my friend just joined small scale IT company as software developer. First month in that company was very hectic. He was working more then 10 hours sometimes there. Prolong sitting on bad chair resulted in spine and neck problems. He has already addressed bad workstation chairs and poor table height but no action was taken. He has helped them in releasing projects which were on deadline within 1.5 month and Now CEO want to fire him and finding his replacement. He cannot resign as he has signed 3 month contract which states that if he resigns within that period he will have to pay double of his earning so far. It’s been just 2 months since joining And CEO can terminate him anytime. And during this time he does not have chance to look for new opportunities as he is focusing on his health during weekends. Please note that employment agreement involved 3 month bond and 2 months of notice period. There is no medical insurance. Please suggest what to do. CEO’s behaviour is very unprofessional