The Difference Between Light, Mid, and Heavy Thermal Weights

The Difference Between Light, Mid, and Heavy Thermal Weights

 A thermal base layer is essential for winter activities like skiing, skating, and hiking in the cold. It sits close to your skin to eliminate moisture and help retain heat. Different weights are available for base layers. Choose the weight that best suits your needs from our range of available options.


A lightweight thermal layer is perfect for mild or moderate temperatures. If the weather isn’t too cold and you’ll be fairly active while wearing the layer, lightweight base layers are a good choice for you. Running and cross-country skiing are two good examples of activities that require this type of thermal wear. For those who get cold easily, you can also use this weight in non-active settings to give you a extra layer of warmth. 


A midweight layer is ideal for cold but not quite freezing temperatures. Midweight thermal base layers are a good middle ground between lightweight and heavyweight, since they are warmer than lightweight thermals but still cool enough to be worn casually or for less extreme activities. You can use this thermal weight for the same activities for lightweight base layers, but in colder conditions.


A heavyweight base layer is ideal in below-freezing temperatures. Also known as mountain weight, these thermals are the thickest and warmest of the three options. Heavyweight thermal layers tend to wick less sweat than lighter weight thermals, but they provide a very warm base layer of insulation. This makes them great for protecting against extreme winter weather and cold winds while you are outside. You could use heavyweight thermals on a winter hiking trip or a similar activity.

Now that you know the difference between light, mid, and heavy thermal weights, you’ll be able to decide which weight is best for your favorite cold-weather activity. Hot Chillys makes thermal base layers for men, women, and children in each of these thicknesses, and we are happy to help you find the perfect winter gear for you.