Sea to Summit Thermolite Reactor Midweight Liner
Sleep Systems
Rating
| Rating: | 9 / 10 |
| Durability | 1.8 / 2 |
| Value for Money | 1.8 / 2 |
| Warmth | 1.8 / 2 |
| Weight | 1.6 / 2 |
| Versatility | 2.0 / 2 |
Sea to Summit Reactor Midweight Liner Review
Comfort has a big impact on whether we get a good night sleep when on a hiking trip. For each of us there is a list of things that will enhance or detract from our perception of comfort. For me the factors include being warm but not too warm (or too cool), the ability to roll over easily (without getting wrapped in my sleeping bag), being ‘covered’ and having a clean place to lay my head. Those of you who don’t use a sleeping bag liner should think deeply about that last point. Your sleeping bag does get dirty and it is a complex exercise to clean your sleeping bag and for its durability, you shouldn’t wash it too often! So the best way to protect your treasured sleeping bag is to use a sleeping bag liner.
The great thing about the Sea to Summit Reactor Midweight Liner is that it will give you a greater range of temperatures across which your sleeping bag will be effective. In fact, this liner will add up to 6° Celcius to the comfort rating of your sleeping bag. So if you only occasionally do overnight hikes in cool temperatures then you can supplement your existing sleeping bag to cover the difference. This means that in addition to extending the life of your sleeping bag by keeping it clean, you’re also extending its performance range.
The Sea to Summit Reactor Midweight Liner is roomy despite being tapered from head to toe. It has a top drawcord which enables you to reduce airflow further and snuggle in for extra warmth. It’s made from a stretch fabric which means restless sleepers won’t feel ‘trapped’. This liner comes in three size:
- Short 178cm
- Regular 193cm
- Long 198cm
Gill will often use her liner over the top of her sleeping pad to stop it slipping around during the night (and to dampen the noise a little) but in may case (Tim) I don’t get that. This liner is so versatile that you can use it for a sleeping bag during the hotter months when most sleeping bags are overkill.
This liner is in the mid range at AUD $99.99 RRP but for the extra warmth and it creates and the additional versatility you will really appreciative this if you are a cold sleeper.
The Sea to Summit Reactor Midweight Liner is without doubt the most value for money hiking kit in which Gill has invested – it is durable, has many uses and is super warm! This liner is always at the top of our sleep system considerations when packing for a colder hike.
We Like
- Beats the lightweight sleeping bag liners for warmth hands down which is the whole purpose
- Drawcord hood with mini cord lock that lets you snuggle down
- Durable
- A great way to keep your sleeping bag clean and extend its life
- Extremely versatile and can be used as a standalone sleeping bag in warm conditions as well as boosting your sleeping bag warmth by 6 degrees celsius!
We Don't Like
- At 370 grams it is a bit on the heavy side when you compare this to the really lightweight liners
Best Uses
- Ideal for use on its own during warm/hot or as a sleeping bag liner that extends your bag warmth
- Extends the life of your sleeping bag by keeping it clean
Buy One
You can purchase Sea to Summit Reactor Midweight Liner online from Amazon Australia, Snowys, or from Wild Earth
Disclosure: We may earn a small commission, at no additional expense to you, if you click through and make a purchase. Please note that our affiliations do not influence, in any way, the independence of our reviews. If we don’t like a product, you’ll hear about it from us!
Investment
AUD $99.99 AUD but they always seem to be on sale somewhere!
Other Versions
Sea to Summit produce a wide range of sleeping bag liners
Sea to Summit Reactor Midweight Liner
Sea to Summit Reactor Midweight Liner in stuff sack
Disclaimer
This review was done with product purchased by Australian Hiker from a retail store
Last updated
13 July 2026