Have you ever wondered how all those mountain climbers stay warm when they seem to bundle up less than you do for a trip to the gym? Insulation is the key to making sure that their body heat is trapped within instead of being transferred out into the colder environment. Nowadays, insulation isn’t just for houses but an essential part of clothing. You’ll be able to dress warmly in any situation with a good pair of thermal underwear for men.

While long johns have been a staple in the world for decades, men’s thermal underwear has evolved over this time. Not only do they keep you warm and comfortable, but many types can be worn by themselves when lounging, paired under a nice suit, or in combination with gym attire when expressing your inner athlete. With multiple colors and patterns, you’re no longer limited to the old standard as a new standard has risen to take its place.

So, here is what you need to know when buying men’s thermal underwear:

1. Proper fit: No matter what you buy, you want it to fit correctly. Many lower-end thermals try to fit as many men as possible which can become a huge issue. While some men may like loose clothing, for thermals this can be a bad thing. The loose clothing allows body heat, warm air to escape your body easily every time you move. Do you want to know what comes back? Colder air which will make you lose even more heat. Your thermal underwear for men should fit close but not too tight.

2. Material is everything: Thermals come in wool or synthetic fabrics. Wool is excellent if it's at a great price. Wool fabric is also a luxury material so that wool thermals can be pricey. Synthetics aren’t new to thermal clothing but have come along way. You can get some fantastic sets of thermals made from synthetic fabrics that are lightweight do a great job of retaining heat.

3. Form and function: When it comes to men’s thermal underwear, insulation, stretch, loft, and even bacteria resistance are things to look for. Insulation is mainly overweight of fabric along with the type of material. Synthetics will have more stretch and flexibility in them which is excellent for the active individual along with wool. Loft is how cloth is woven to maintain insulating capabilities and gives thermal underwear for men their moisture-wicking function. Bacteria resistance is a must as the material keeps moisture away while providing warmth which prevents bacteria from growing.

4. Style: Men’s thermal underwear come in sets, tops, pants, and even different colors and patterns. You can choose whether to wear a whole set or need only one piece of them. It's all up to you and your needs over winter.

Buying thermal underwear for men is an essential part of staying warm and comfortable during the chilly months of the year or for cooler days. Whether you are going to lounge around the house, take in a sport’s event, or hit the gym, thermals will keep you warm and comfortable all day.