B&M sells its own range of branded thermals under the "HEATsaver" banner. They're not currently available to buy online, but you can find items from the range in most large B&M stores. Lor53 Lovely colour Love the quality and the brushed fabric inside will be lovely and warm, nice grey shade, hope my friend likes them it’s a Xmas pressie

Breej Warm, comfy Extremely warm and comfortable and great fit. I’m a size 12-14 and the 12 was perfect. Lovesunnydays90 Cosy warm leggings These are fabulous. Really warm and smart enough to go out in. Lovely material and so cosy. Brushed: Brushed fabric is soft, comfortable, and retains heat: “A brushed, formfitting pant traps warmth between your legs and the leggings, and keeps the wind chill out,” says Faist. Debraleeds BEAUTIFUL HEATGEN PLUS PRODUCTS I bought a grey pair of leggings, they feel luxurious and so comfortable.ModernMum2 Incredibly comfy and warm Love this, super soft, keeps me nice and warm, not bulky, good for layering too. mumwholovesmns Feel and touch The feel and touch of these leggings are lovely. They are much warmer than normal leggings, but are not chunky and unflattering. I would highly recommend whilst colder weather is still upon us.

hairlady Heatgen Thermal Leggin Nice soft leggins. Good fit. Feel warm when wearing despite fabric seeming thin. Shopqueen01 Great value super soft warm leggings Lovely & warm especially in the colder months, great quality not too thin does exactly what it says keeps your legs cosyI tested different items under different conditions (eg sitting at home and going out for a winter walk), as well as piling everything in one shot for the purposes of these photos. But let me tell you, having snuggled up in full B&M thermals for these photos and felt their thermal joy, I think I'm going to stay dressed like this until March. Having a pair of warm leggings is clutch for outdoor workouts because not only will they keep you warm, but they’ll also keep you comfortable and focused on your workout—not on how cold you feel,” Kaitlyn Faist, a NASM-certified personal trainer and runner from Chicago, tells SELF. EmmaH78 Warm and cosy Love these leggings for wearing round the house or as an extra layer on cold days. Stretchy, cosy and a good fit. ComfortDevotee49 Snuggy! Bought for an elderly friend who seems delighted with them. I already have two pairs. Still, there are a few common factors to keep in mind that can help you choose a great pair of leggings, Faist says. Here’s what she looks for: