SOL Emergency Bivvy review

What it is and who it suits

The listing this review reads is the Red Cross Store's page for the SOL Emergency Bivvy with Rescue Whistle, which repeats the maker's description. It calls it an emergency bivvy to keep you warm and dry, with sealed seams and a waterproof material, a bright orange color for visibility, a tinder paracord drawstring and a survival whistle to signal rescuers. It says the bivvy weighs less than 4 ounces and is smaller than a soda can.

It suits a hiker, driver or commuter who wants a shelter that costs almost nothing in space. This review is researched, not tested. The maker's own site could not be read, so the Red Cross Store page and the National Weather Service are the sources, and we cannot confirm that this listing is the same SKU as the one our comparison page links to.

What the maker says it does

The description says the bivvy reflects 90 percent of body heat back to you and traps warm air to keep out rain, wind and cold. It says the material is ultra quiet and tear-resistant and will not shred if punctured. The 90 percent figure is the maker's claim, and the page does not cite a test or say how the figure was measured.

Weight is given two ways: only 4 ounces in the headline and 0.27 pounds in the details table, which also lists a packed size of 3.6 by 6.2 by 1.2 inches. The page does not explain the difference.

What the page does not say

The page does not give the opened size of the bivvy, a temperature rating or a statement about reuse. A sleeping bag such as the Coleman Brazos on our comparison page carries a temperature rating from its maker; this bivvy does not. The page also describes a waterproof, sealed material but says nothing about condensation inside on a long stay. SOL's separate Escape Bivvy with Hood is listed on our comparison page as a breathable design.

Where it fits, and where it does not

The National Weather Service advises dressing in layers in extreme cold, seeking shelter from the wind and changing out of wet clothes as soon as possible. It describes hypothermia as a body temperature below 95°F that needs immediate medical attention, and says to move the person to a heated location and warm the center of the body first. A bivvy is a stopgap in that picture: it helps keep heat in while you wait for rescue or reach shelter, but it is not a treatment.

It belongs in a go-bag or a winter car kit rather than as the plan for a cold house, where our stay warm without power guide matters more.

How it compares with the other picks

On our emergency blanket comparison, a plain foil blanket is an open sheet, while a bivvy closes around you. The Go Time Gear bivvy, with its own review, is the closest rival. A real sleeping bag, such as the Coleman Brazos, is the better choice for a planned night out, and SOL's 90 percent reflective blanket is a lighter, open alternative.

Verdict and who should skip it

A sensible, nearly weightless backup for every bag if you accept the maker's heat claim as a claim. Skip it if you need to sleep out for days, want a rated temperature, or want something to use more than once; the page promises none of those. For a planned night in the cold, bring a sleeping bag.

Does the SOL bivvy really reflect 90 percent of body heat?

That is the maker's claim, repeated on the Red Cross Store page, which does not cite a test. Treat it as an emergency barrier against wind and rain, not a rated sleeping system.

How big is it when packed?

The Red Cross Store lists a packed size of 3.6 by 6.2 by 1.2 inches and a weight of 0.27 pounds. The text says it weighs less than 4 ounces and is smaller than a soda can.

Does it come with a whistle?

Yes. The description says a survival whistle is included to signal your location to rescuers, and a tinder paracord drawstring is included for starting a fire.

Can it replace a sleeping bag?

No. The page gives no temperature rating and calls the bivvy an emergency item. A sleeping bag with a stated rating is the better choice for a planned night in the cold.