Sea to Summit Reactor Plus Thermolite Liner


Weight 9.3 oz / 263g



This is a great addition to any sleeping bag OR used…

Rating: rated 5 of 5 stars
Price Paid: $50

This is a great addition to any sleeping bag OR used by itself.

My husband and I backpack a lot but did some car camping recently at Shenandoah NP.  I had just purchased the Reactor Plus at EMS and was super stoked to try it out. My husband, on the other hand, purhcased the cooler bag (poor choice). It dropped to about 49 degrees that night and I was VERY comfortable.

Although I'm ususally a cold sleeper, I slept the whole night thru with this one. (My husband, on the other hand, was a bit chilly.)

It is definitely worth the investment, especially if your current sleeping bag needs a little something to take the edge off during the cooler months. OR, if you're like me, and like to have a thin layer during the warmer(ish) months, but don't want to use an actual sleeping bag.


Really warms up a bag when you are on the cold edge…

Rating: rated 4.5 of 5 stars
Source: bought it new
Price Paid: $55


Really warms up a bag when you are on the cold edge of what your sleeping bag can handle.


  • does what it says, warms up the sleeping bag


  • can get tangled up in the material

This bag liner is amazing. It really warms up the bag. I was camping with this and my Marmot Atom (40°) and the temps got down into the high 30s. I woke up in the middle of the night chilled so I slipped into this and immediately felt more warmth. Not long after I was getting really warm and had to vent my sleeping bag. I would never guess such a thin fabric would hold in so much heat.

The bag liner packs up pretty small. Not as small as a silk bag liner but not as big as a sleeping bag either. I am tall at 6'1" but this liner fit me just fine.  

On the down sides, you have to slide into this from the top and because it is a relatively thin material, if you toss and turn you can end up tangled up in it. Personally I would rather be warm than tangle free but that's just me.  Some might find it restrictive.  

I definitely recommend this liner for shoulder seasons or any time you are pushing your sleeping bags to their cold limits. Nice insurance to keep you warm through the night.