Heater not working -orange half moon shaped light with line and wavy lines through it

I turned on my car this morning as usual to warm it up and defrost and when I got outside, the air circulating in the car was cold. :/

the heating was also cold when I turned the dial. It warmed up once I started driving.

When I sat in traffic for a minute, it cooled down again :/.

There is an orange light on the display, it's like a half moon sort of with a line next to it with wavy lines perpendicular going through it - it's on the bottom of the display area.

Does anyone know what this means and anything I can do to get my car to heat and defrost again?



I recently had the crankshaft sensor replaced (3 weeks ago) but nothing else unusual happened and it was working just fine the night before.



Thanks for any advice! :) :confused: