That's right. You have to check with the CAA as to what they approve but essentially it has to be + 5700kg and have a 2 pilot requirement from the manufacturer.
Now, before you all go rushing off. I'll give you an idea as to what I wear flying night freight. It's winter here...
Motorcycle boots.
Long thick woollen socks
Long johns
Wool mix trousers
T-shirt
Flying shirt
Polyester jumper (work issued)
Wind proof 300# fleece
Flying jacket (work issued)
Scarf
Gloves.
We cheer when the temp is in the positives and the RVR is +1000m.
Believe me, I have never done as many fair dinkum ILS's in my life and the weather is interesting. Ice is common place below 10,000' too.