Thanks for your question on Healthcare Magic.
I can understand your concern.
No, this is not thermal
shock.
In my opinion, you are mostly having
stress and exertion
induced tachycardia which is giving you feeling of heart clicks.
But since it is not settled after 30 minutes, we should definitely rule out
arrhythmia (rhythm disturbances in heart). Because arrhythmia can cause palpitations, clicking feeling of heart, pounding sensations in chest etc.
So better to go to emergency room and get done ecg and 2d echo.
If these tests are normal then no need to worry for arrhythmia.
You are mostly having stress and exertion related tachycardia.
Don't worry, with rest, you will be alright.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.