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Reviews > Clothing > Jackets and Vests > MontBell UL Thermawrap Jacket > Owner Review by Cheryl McMurray

Owner Review By Cheryl McMurray  
SEPTEMBER 30, 2011


Name:  Cheryl McMurray
Age:  52
Gender:  Female
Height:  5 ft 8 in (173 cm)
Weight:  145 lb (66.6 kg)
Chest measurement: 38 in (97 cm)
Arm length:  24 in (61 cm) from wrist to arm joint
Waist: 33 in (84 cm)
Hips: 41 in (104 cm)
Email Address:  cherylmcmurray2ATgmailDOTcom
City, State, Country:  Garden Grove, California, U.S.


I've been backpacking and hiking for four years, mostly on weekends year around.  Overnight trips are usually three day, two night trips in the Eastern Sierras with 32 lb to 40 lb (15 kg to 18 kg) loads depending on the season.  One class two rock climb with a day pack is common.   Day hikes are 10-15 mi (16 km to 24 km) in the San Bernardino and San Gabriel Mountains with loads of 15 lb to 20 lb (7 km to 9 km).  I'm a tent style camper and have experienced snow, freezing temperatures, winds (once was gale force), light rain, but mostly fair weather so far.


Manufacturer:  MontBell Co
Manufacturer Website:
Year of Manufacture:  2009
Listed Weight:  8.8 oz  (250 gm)
Actual Weight:  8.8 oz (2.50 gm)
Size:  Medium Men's
Size Measurements:  Chest 38 in (97 cm) to 40 in (102 cm), sleeve 34 in (86 cm), waist 31 in (79 cm) to 33 in (84 cm)
Color:  Dark Navy
MSRP:  $145.00 US


The Montbell U.L. Thermawrap jacket is a synthetic light weight jacket that is very compactable, wind and water resistant.  The material which is 15-denier Ballistic Airlight calendered nylon, is very soft and quiet when moving   The filling is Exceloft synthetic and although very light, it claims to be very warm.   

*The current version of the jacket is slightly different than the model that is reviewed here.


The Thermawrap jacket came with a very light, small stuff sack made of the same material and color as the outer shell.  The jacket is very soft with a minimalistic design featuring two fairly deep hand pockets (without zippers) along with cuffs and hem that use wedge shaped stretch panels to help customize the fit.  The one way front zipper comes all the way up to the top of the micro-fleece lined collar and the jacket will compact down to 4.3 in (11 cm) x 8.3 in (21 cm) in its stuff sack.

Jacket with stuff sack
In stuff sack next to 33 oz (1 l) bottle
Jacket with stuff sack
In stuff sack

Micro fleece lined collar Wedge shaped panel at waist and arm cuffs
Fleece lined collar
Stretch panels


The measurements of the men's medium jacket seemed to fit me better than a women's large so that is why I chose the men's version.  It's not a perfect fit as the waist/hip area is a little snug but the elastic panels in the jacket allows the jacket to move with me without feeling tight.  The sleeves are nice and roomy but are a little long, however, I'd rather they be too long than too short.  I always wear a baselayer underneath and prefer room for a light fleece pullover or jacket as well and the size of this jacket enables me to do that.

Jacket how it fits on me


I have used this jacket
over the last 3 years on no less than 15 backpacking trips in the Eastern Sierras, San Gabriel Mts and San Bernardino Mts, all in California.  The temperatures that I have encountered with the jacket have ranged from 28 F (-2 C) to 45 F (7 C) with elevations from 6,000 ft (1,830 m) to 11,000 ft (3,350 m).  I have included below my experience with the jacket on 3 of those backpacking trips.  I also carry the jacket on all of my 3-season day hikes for potential use on summits if the winds are blowing and as an emergency jacket in case of an unplanned bivy overnight.  I am happy to report that the latter has never happened yet.


Location: Round Valley, San Jacinto Mountains, Southern California
Type of trip:  Snow camping trip
Elevation: 9,200 ft (2,800 m) to 10,600 ft (3,230 m)
Temperature: 35 F (2 C) to 55 F (13 C)
Conditions: Cool and breezy at camp and cold and windy on the summit

Location:  Dry Lake, San Bernardino Mts in Southern California
Type of trip:  Late summer trip
Elevation:  9,100 ft (2,775 m)
Temperature:  28 F (-2 C) to 60 F (16 C)
Conditions:  Sunny, cold mornings

Location:  Hungry Packer Lake, Eastern Sierras near Bishop, California
Type of trip:  Late summer trip
Elevation:  11,000 ft (3,350 m)
Temperature:  39 F (4 C) to 70 F (21 C)
Conditions:  Sunny, partly cloudy, cool evenings, colder mornings

During the Round Valley trip I left my larger down jacket at home and opted to test this jacket in light winter conditions.  I was expecting a low temperature in the high 20's F (-2 C) but it never actually got down to freezing.  I had a reading of 38 F (3 C) inside my tent in the morning so I knew it was slightly colder than that outside the tent.  I first used the jacket when I sat down to dinner with a light wool base layer, light fleece pullover, and then the Thermawrap jacket over that.  It kept me comfortable until the sun began to set then I needed to add an outer shell over it.  I still felt a little chill but was not uncomfortable.  As I got ready to crawl into my sleeping bag, I noticed how nice and easy this jacket was to put on and take off due to its less bulk and weight.  In the morning, I put the jacket on right away and within a few seconds my body heated the jacket up and I crawled out of my tent.  From this point, I began to see how well the jacket worked.  Heat generated from the slightest movement was retained and when I was doing more than moderate work I needed to unzip the front a little as it was getting too warm.  I started off for a snowshoe day hike but left the jacket compressed in my pack until I was at the summit.  After reaching the summit I immediately put the jacket on due to the winds and stayed very warm not feeling any of the wind affects.   I kept the jacket on for the descent thinking that I would be using less energy but even with moderate effort I became overheated and had to put it back in the pack.  I found on this trip that it worked well at camp and on the peak summit when I wasn't generating a lot of body heat.

Breakfast at 5 am

Breakfast at 5 am

The jacket was used in the evenings and mornings on the other two trips.  The temperatures drop quickly once the sun goes down so this jacket is always on after 6 pm.  I always wear a  zippered fleece hoody underneath and find it keeps me warm down to about 40 F (4 C) in the evenings.  I have now taken to sleeping in the jacket with the fleece hoody underneath while in my sleeping bag and it does help me sleep warmer as I tend to sleep on the cold side.  I'm always up around 4:30 am ready to stargaze and make breakfast so I do encounter the coldest part of the day.  I am able to sit outside with just the fleece and Thermawrap jacket on with a temperature of 35 F (2 C) or higher.  It got down to 28 F (-2 C) one of the mornings and due to some week long thunderstorms before my trip, the ground and consequently the air was very moist, making it feel colder.  I added a light shell over the Thermawrap and that combined with two cups of coffee made me feel very comfortable.

Evening at Dry Lake
Action shot.  Freezing temperature
Evening at Dry Lake
Action shot.  Below freezing temps

I bring the jacket on every 3 season day hike in case the weather and winds get cold or I have to do an unplanned bivy (so far I've escaped that fate).  It packs down so small and with a weight of under 9 oz (255 gm) is hardly noticed in my day pack.  I do many day hikes up to 10,000 ft (3,050 m) at Mt Baldy in the San Gabriel Mts and often the winds are strong at the summit, making it pretty cold when I want to take some time and just enjoy the views up there.  This jacket has come in handy on many of those occasions and is so easy to get out and put on.  The manufacturer states that the material is water resistant.  I have not had this jacket in any light rain or mist but it does bead up when water droplets are put on it.


The washing instructions for the jacket are to machine wash and tumble dry on a regular setting.  Since I have been using it, I've only washed the jacket about 4 times.  I usually use a delicate cycle for both washing and tumble drying and it washes up really nicely. 

The only possible abuse that the jacket has been exposed to is leaning up against rocks or tree trunks during dinner and breakfast.  Although the material appears delicate, I've had no issues with snags or tears.  The color has remained the same as the first day I used it and the seams are still holding up very well. 


Size, weight and compacted size
Softness of the material
Ease of putting it on and taking it off
Will keep me warm down to 35 F (2 C) with a fleece layer underneath
Adds warmth to my sleeping bag when sleeping in the jacket




The Montbell U.L. Thermawrap jacket has become a staple on my 3-season backpacking and day hiking trips.  It has handled temperatures as low as 28 F (-2 C) with a fleece layer underneath and because it is so light, I never have to decide if I want to take it or not.  It always goes.  It is somewhat expensive but I think the durability and quality of the jacket can justify spending the money.  I do recommend this jacket.

Read more gear reviews by Cheryl McMurray

Reviews > Clothing > Jackets and Vests > MontBell UL Thermawrap Jacket > Owner Review by Cheryl McMurray

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