Weather forecasts for Friday predict three to five inches of snow during The North Face Ultra-Trail du Mont Blanc (UTMB), the 100-mile trail race around 15,771-foot Mont Blanc through France, Switzerland, and Italy. That makes gearing up for the endurance event even more complicated.

Breckenridge, Colorado-based ultra trail runner Helen Cosplich, sponsored by The North Face, will attempt her second UTMB this year. Her husband and six-year-old daughter are here in Chamonix to cheer her on.

The event starts at 6:30 p.m., as temperatures drop, so that the 2,300 competitors will run through the night early on, before they are exhausted and more susceptible to hypothermia. This year, officials recommend that racers bring a fourth layer, especially for the cold night.

The North Face actually designs their running gear for this decade-old trail race. The trick is to be warm enough, but not wet and sweaty, and as light as possible. Here’s what Helen will be wearing.

1. Base layer – The North Face Better Than Naked shirt with Flash Dry, which accelerates sweat evaporation
2. Arm warmers, which are easy to pull off and on for an extra layer
3. Mid layer – Aires long-sleeved shirt made with wool and Flash Dry
4. Jacket – The North Face Featherlite waterproof, seam-sealed shell
5. Socks – Ultralight Mini Smartwool socks (with a spare pair to change into)
6. Compression calf sleeves
7. Rain pants
8. Shoes – The North Face Hyper Track trail shoes with Vibram soles, one pair

We wish Helen and all the races luck and good conditions!