"This is usually caused by low refrigerant levels, insufficient airflow over the coils, defective fans or components and dirty filters which restrict air flow. It's important to make sure your AC is always well maintained and checked regularly to avoid an unwanted freeze!"
For many, many years, I would not let them give me Novocaine because of the needle. A good dentist will have his/her assistant numb your gums with a cotton swab and you will not feel the needle stick.