Bicycle Mechanics - How to prevent flats from thorns

Just recently was forced out of an MT bike Event due to flat tires 3 times in 15 minutes

first time , thought it was just a pinch, so just simply tossed the tube and replaced it (front tire)

then within riding for 4 minutes that tire went flat again, i look at tire and found a very fine thorn in my tire, (should have checked my tire prior) anyways used my second spare tube to fix it
then with 5 minutes of riding, my rear tire went
so i was out of tubes and basically had a long long walk out of the bush back to civilization

After a check of that tire , it was a small thorn, now my tires i kept at 35 to 40 psi
but what can i do to prevent thorns?

Would using slime in my tube work? or any other strategies? thanks

A tire liner might. Always carry a patch kit for those days when it goes to hell.

I can't stand slime. My spouse used slime when we were in Texas last winter and he kept getting flats. I went out to the shed one morning and slime was leaking out of holes in his tire. Yucky mess. And pulling out the slime filled tube wasn't much fun either.

Good tires, kevlar liners.

Tubeless sounds to be the best solution for you.

For any puncture, you need to find out what caused it, and remove the cause if it can cause future issues. You realised this too late from the sound of it, but it's useful for next time.