What is an unsafe heart rate of a 12 year old with hyperthyroidism?

For a 12-year-old with hyperthyroidism, a resting heart rate above 100 beats per minute may be considered unsafe, especially if accompanied by symptoms like palpitations, chest pain, or dizziness. Hyperthyroidism can cause tachycardia, and sustained elevated heart rates can strain the heart. It's essential for the child to be monitored by a healthcare professional to manage their condition effectively. Any concerns about heart rate should prompt immediate medical evaluation.