How to check if there is a collider above and then uncrouch

Hello, first sorry if I ever make a mistake because I'm not an English .. so, let me just introduce you the question. I have a simple but very nice Crouch sytem for my character, but when I stand/uncrouch and there is some kind of ceiling above the character (collider), the char goes through the colider and stucks there until I crouch and go somewhere else where there is not a collider above. I tried some ceiling checks, but they didn't help in any way .. so can, you someone of you guys help me, here is my code:

 private bool isCrouching = false;
 private Transform theTransform;
 private float charHeight;
 
 void Start()
 {
     theTransform = transform;
     charHeight = CharCont.height;
 }
 
 public void Update()
 {
         float h = charHeight;
         float speed = WalkSpeed;
         
         if(Input.GetKey (KeyCode.C))
         {
             h = charHeight*0.5f;
             isCrouching = true;
         }
         else
             isCrouching = false;
         
         float lastHeight = CharCont.height;
         CharCont.height = Mathf.Lerp (CharCont.height, h, 5*Time.deltaTime);
         theTransform.position = new Vector3    (theTransform.position.x, theTransform.position.y+(CharCont.height-lastHeight)/2, theTransform.position.z);
 }

So is there a way to implement a checkForCeiling system, or anykind of system that prevents character to go through ceilings?