I work in a water park where we have lots of spanish only speaking kids. They run and just saying "No Corre" doesn't not only work. With english speaking kids, we tell them why we don't want them to do something. I'd like to do the same for spanish speaking kids.
Negative imperatives in Spanish are always invoked by using the subjunctive mood:
Don't run = No corras/corran.
If the indicative is used, it means we are stating a fact.
Now, the construction want + subject + infinitive invokes the subjunctive mood:
I don't want you to slip = No quiero que te/se resbales/resbalen.
For the last part, get hurt = lastimar, so with the subjunctive implied, putting all together we get:
Don't run, because I don't want you to slip and get hurt = No corran/corras, porque no quiero que se/te resbalen/resbales y (se/te) lastimen/lastimes.