See also:

Freeing a frozen door lock
To prevent a door lock from freezing, apply deicer through the key hole. If the lock becomes frozen, heat the key before inserting it into the key hole or use the remote keyless entry keyfob. ...

Never leave these keys in the vehicle.
As many as 4 Intelligent Keys can be registered and used with one vehicle. The new keys must be registered by a NISSAN dealer prior to use with the Intelligent Key and NISSAN Vehicle Immobilizer ...

Intelligent Key system (if so equipped)
- Radio waves could adversely affect electric medical equipment. Those who use a pacemaker should contact the electric medical equipment manufacturer for the possible influences before u ...