Heater blows cold air when the car is stopped on 2006 Lexus IS350

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
the heater will blow cold air at stop lights but work again once the car is moving.
(3) Answers
First thing to do- Check the antifreeze level in both the overflow and the radiator. Top up as necessary with correct antifreeze type. If fluid is excessively low, get your vehicle to service shop to check for leaks.
same exact thing happened to mine. with the car engine ice cold check the antifreeze level. it WILL BE LOW! fill it to the cold level using ONLY TOYOTA GENUINE COOLANT! turn the car after is filled accordingly, drive it and voila problem fixed.
Hey Katy,,,,I haven oseven 350 does the same thing ..hit the off button due to it mysteriously going to the ac...then go back to the heat...check ur dual temps too....cya fr NY!