US Embassy?

Yes, the Embassy will help

First of all the Embassy will contact the patient's insurance company. They will also contact the patient's credit card company as many credit cards have built in travel insurance if you book your flight using the card. They will also contact the patient's employer to find out if the company insurance policy covers medical expenses overseas. They will also contact the patient's GP back home to inform them of the situation and make sure the patient does not have any allergies or preexisting conditions

If you know of an American in the hospital in Dubai you need to immediatley contact the American Citizens Services office at the US Consulate in Dubai on DubaiACS@state.gov with all information you have - their name, the name of the hospital, their employer, their contact details, etc and within 24 hours the Embassy will send a representative to the hospital to check on his condition, get his records to send to his GP back home, get his insurance information to contact the insurance company to cover any expenses, and get back to you with an update on their condition. Alternately you can ring them on +971-4-309-4000 but only between the hours of 8:00 - 10:00 Dubai time, Sunday - Thursday so it's better to just email with all details you have

EDIT -- Looking at your other question you are being scammed. If he's in the military his insurance will cover any medical bills and if it's anything serious he would be transferred to the US military hospital in Kuwait. You are not talking to a soldier if he's asking for money for medical treatment.

No it would no be under serious responsibility