Hi and welcome to the site. My name isXXXXX and I'll be providing medical information for you today.
It's important that you take him to the emergency room for medical attention.
He may have ingested something that is causing this combination of symptoms.
You can call 911 or have someone drive you there as soon as possible.
999 or 112 in the UK
He has been fine most of the day and he hasn't been unattended, do you know what can be the reason for this?
So but he does not sound well and he needs medical attention.
If he has racing heart, racing breathing and is very tired, he needs medical attention.
It's better to be safe than sorry.
Whatever the cause is, it requires a doctor to examine him to determine.
There is a very long list of possible causes of rapid breathing and rapid heartbeat.
This can range from problems with the heart, the lungs or the brain.
If he is also lethargic, it's a sign that he is not well at all and needs medical attention.