Tell them to think twice before striking. Think about how long they will have work after the strike to make up any loses if they are out a week, 2 weeks, a month or longer.
Have seen people vote to strike for a higher wage than company was offering, win the amount of raise they wanted, work 3 years at the new rate and still lost money. They would have been better off with the company offer or even with no raise. Work the medical issue into some form of how long they have to work to make up any loses if they strike or don't take the agreement you all have arrived at.