Born to be Wild

Ted finishes his first year gross anatomy exam just in time to head to New Orleans for Spring break. It has been his dream to mimic the famous scene in  Easy Rider, except that Ted does not own a motorcycle.  Nevertheless, he does plan to drive his 30 year old  Mustang from D.C. to New Orleans. He powers up, cranks up Steppenwolf in Spotify, but One hundred miles into the 1000 mile trip the air conditioning gives out. Ted takes his shirt off and lowers the windows as he continues his adventure. He drives straight for approximately 10 hours during the middle part of the day, with a blistering sun  and a temperature of close to 90 degrees. Upon reaching his hotel, it is freezing inside and he dons his jacket, rushes six flights of  stairs (due to broken elevator) to shower and hit the town that night. Upon reaching his room, Ted notices a strange sensation in his left arm, and he thinks he is experiences a heart attack. He thinks that perhaps the stress of preparing for the exam, the ten-hour drive in blistering heat, and rushing up the stairs has caused a heart attack. Of that he is sure; what else can possibly be causing the extreme pain in his left arm? Ted calls the front desk and tells them he is in mid-cardiac failure and to please call him an ambulance. When the emergency team arrives, Ted explains the situation and is asked to remove his jacket. The first responders immediately recognize the reason for Ted’s discomfort and inform him he is not experience cardiac symptoms. Assuming Ted’s pain is nothing more than a severe sunburn, which of the indicated nerves was likely affected by the sunburn leading to his assumption of a heart attack?

Identify the nerve responsible for referred pain to the T2 dermatome.