A North Texas mother who was arrested after Frisco police said she intentionally left her 15-month-old child in a hot car earlier this month is now facing a first-degree murder charge.

According to an arrest affidavit for Vanessa Esquivel, 27, she allegedly tried to cover up evidence that she was at work as a massage therapist during the time her toddler was sitting outside in a hot car.

Authorities alleged that Esquivel tried to cover up the crime and also believe that after leaving work at the spa with her dying child in the car, she stopped at McDonald's and ordered food before going to the hospital.  

The boy was left in a vehicle on a 95-degree day for as long as three hours, according to the affidavit, and he was already dead when his mother took him to a Plano hospital. 

The arrest affidavit said Esquivel brought the boy to the emergency room at Medical City Plano around 5:30 p.m. on Aug. 16. She told the medical staff that her toddler did not seem to be feeling well, and that she had been driving him around during the day in a hot vehicle since her air conditioning did not work. She also told medical staff and Plano police officers that she had been with the boy the entire day.

Medical staff said the child was already dead by the time he got to the hospital and his core temperature was measured at over 106 degrees.

A Plano police officer noticed she was wearing a Hand and Stone Massage and Facial Spa uniform and asked her if she went to work, but she insisted she did not go to work that day. Officers later contacted the business and learned that Esquivel worked between 1:45 p.m. and 4:15 p.m. that day. A coworker told police that Esquivel stayed inside the business, and she did not return to her vehicle until she left for the day.

The affidavit said authorities found out Esquivel contacted the spa, saying her son had passed away the previous day. She said she was "between a rock and a hard place" and was unable to find childcare for him. 

Esquivel said she left the victim in her vehicle in the parking lot with the air conditioning running while she served two clients. She told the employee that the police were investigating her, and she asked the employee not to leak her phone call.

An autopsy determined that the child's death was the result of prolonged exposure to heat. Esquivel has been in the Collin County Jail since her arrest.