I grew up in Wisconsin. Midwest winters are a primary reason I moved to the West Coast. Even in Washington it doesn’t get that cold. I wear shorts and flip flops almost all year. Below 40 I start wearing shoes and pants.

I’m away from my PC so I can’t name it but there’s another plugin similar to Tree Style Tabs. The creator claims that TST takes up a lot of resources. I do notice Firefox taking a lot of CPU/mem but that’s probably my fault. I’ve tried both and either works well.