Heart rate in teens

My boy, 16, is a happy and active teenager but he’s been worrying allot recently about his heart rate. Yesterday he went on a long bike ride (mostly uphill) and it was a hot day with the heatwave in the UK right now, his heart rate reached 195bpm at one point of the ride as recorded on his Apple Watch. He’s recently been anxious about his heart health and I think most the fear comes from his dad who suffered a cardiac arrest a few years ago. I have signed him up on the waiting list for a cardiac screening in hopes to put his mind to rest as every little pain he gets anxious.

I guess I’m writing this post to ask others where to go next? Has anyone ever experienced similar? He’s very bright and I don’t want this fear getting to him.