Being cold is not a criteria for not doing CPR, I cannot post links but you can do a quick google, especially not under the New York State BLS protocols under which EN operate.
The other signs of certain death, take time to set in.
The saying goes, your not dead, until your warm and dead.
In fact, hospitals that were doing the hypothermia protocol for patients in cardiac arrest, had to work up the patient until they were warm, which would take a long time and made the staff go through many code carts.