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Quick answer: For a one- or two-person ice shanty or hunting blind, the Mr. Heater Portable Buddy (MH9BX) is the pick most people need: two heat settings, an oxygen depletion sensor and a tip-over switch [7]. Whatever you buy, give it the fresh-air opening its manual specifies, never run it while you sleep, and bring a battery carbon monoxide alarm [3][4].
At a glance
- Michigan CO poisonings, 2023
- 481 unintentional cases, including 31 deaths [1]
- Portable heater CO deaths, U.S.
- 33 in 2020, second only to generators (92) [2]
- Never while sleeping
- CPSC: no portable heaters while sleeping in tents, campers or vehicles [3]
- Certification
- Mr. Heater says all Buddy heaters are certified to CSA/ANSI standards [5]
- Recall excluded
- The Big Buddy (MH18B) was recalled for repair in 2005 [9]
Why this matters in Michigan
Carbon monoxide is a real winter risk here. The Michigan Department of Health and Human Services counted 481 cases of illness from unintentional carbon monoxide poisoning among Michigan residents in 2023, including 31 deaths [1]. Nationally, the CPSC says portable heaters were tied to 33 carbon monoxide deaths in 2020, the second-highest count for any product type after generators [2].
The places Michiganders use small propane heaters are the riskiest ones: ice shanties, deer blinds, cabins and campers. The CPSC says people die every year from carbon monoxide from portable camping heaters used inside tents, campers and vehicles [3]. Mr. Heater’s manuals list fishing huts, cabins, tents and vans as places the Buddy heaters may be used, but only with the vent opening each manual specifies [6][7].
How we chose
- Built and certified for enclosed spaces. We only picked heaters the maker sells as indoor-safe for the U.S. Mr. Heater says all Buddy heaters are certified to CSA/ANSI standards [5], and the manuals we checked name the standard (CSA 4.98) [6][7].
- Oxygen depletion sensor and tip-over shut-off. Every pick has both [6][7][8][10].
- Vent opening from the manual. We list the minimum fresh-air opening each manual requires, because that is what keeps the heater safe in a small space.
- Recall check. We searched the CPSC recall database for each model on November 2, 2026. The Mr. Heater Big Buddy (MH18B) was the subject of a 2005 recall to repair [9], so we left it out even though current units are sold. None of the four picks has a recall on record.
Our picks
Best for: A one-person shanty or blind
Mr. Heater Little Buddy (MH4B)
The smallest Buddy, with a single setting and the smallest vent requirement of our picks.
- 3,800 BTU per hour [6]
- Needs a fresh-air opening of at least 4 square inches (for example 2 in. x 2 in.) [6]
- Oxygen depletion pilot and tip-over switch [6]
Safety check: Manual states it is certified to CSA requirement 4.98, Gas Fired Portable Heaters for Recreational or Commercial Use. No CPSC recall found for the MH4B (checked 2026-11-02).
Watch out: One heat setting and a small output, so it won't keep up in a drafty shanty on a below-zero day. Sold for the U.S. except Massachusetts [6].
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: Most ice shanties and hunting blinds
Mr. Heater Portable Buddy (MH9BX)
Two heat settings let you start on high and drop to low once the space is warm, which also stretches a 1 lb cylinder.
- 4,000 or 9,000 BTU per hour; heats up to 225 sq. ft. [7]
- About 3 hours on high and 6 hours on low per 1 lb cylinder [7]
- Needs a fresh-air opening of at least 9 square inches (for example 3 in. x 3 in.) [7]
- Oxygen depletion sensor, tip-over shut-off; 3-year limited warranty [7]
Safety check: Manual lists CSA 4.98 certification. No CPSC recall found for the MH9BX (checked 2026-11-02).
Watch out: The manual says it may shut off above 7,000 ft, which isn't an issue in Michigan, and that a refillable propane cylinder must never be brought indoors; use 1 lb cylinders inside [7].
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: A cabin or camper you heat for a few hours at a time
Mr. Heater Buddy FLEX (MH11BFLEX)
More output than the Portable Buddy, so it covers a larger room, with a separate fresh-air requirement for high and low openings.
- 8,000 to 11,000 BTU per hour; heats up to 275 sq. ft. [8]
- About 2 hours on high and 3.5 hours on low [8]
- Needs a fresh-air opening of 11 square inches at the ceiling and at floor level [8]
- Oxygen depletion sensor, tip-over switch; 3-year limited warranty [8]
Safety check: Mr. Heater lists it as indoor-safe (excluding Canada and Massachusetts) and says Buddy heaters are certified to CSA/ANSI standards [5]. No CPSC recall found for the MH11BFLEX (checked 2026-11-02).
Watch out: The manual gives a minimum ambient temperature of 0°F [8], so it may not be the right heater for an ice shanty on the coldest Michigan mornings. It burns through a 1 lb cylinder quickly on high.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: Larger blinds and two-person shanties
Mr. Heater Hunting Buddy (MH12HB)
The most output of our picks, with electronic ignition and two heat settings. Mr. Heater lists hunting blinds, deer stands and fishing among its uses.
- 6,000 to 12,000 BTU per hour; heats up to 300 sq. ft. [10]
- Oxygen depletion sensor and tip-over safety switch [10]
- Electronic ignition; connects to a 20 lb cylinder with an optional hose [10]
Safety check: Mr. Heater lists it as indoor-safe and says Buddy heaters are certified to CSA/ANSI standards [5]. No CPSC recall found for the MH12HB (checked 2026-11-02).
Watch out: Only a 1-year limited warranty, shorter than the other Buddy heaters [10]. Mr. Heater doesn't list a run time on the product page, and we couldn't find the vent requirement on it either, so check the manual in the box.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Buying guide
- Size to the space, not the weather. A heater that is too big for a small shanty uses up oxygen faster. Start with the smallest heater that keeps you comfortable.
- Make the vent opening before you light it. Each manual gives a minimum fresh-air opening; the larger heaters want openings both high and low [7][8].
- Keep the propane outside. The manuals say never to bring a refillable propane cylinder indoors and to store cylinders outdoors [7].
- Buy the right version. Massachusetts and Canada versions of these heaters are labeled for outdoor use only.
Sources
- Michigan Department of Health and Human Services: Carbon Monoxide Data
- CPSC: Carbon Monoxide Fact Sheet / Questions and Answers
- CPSC: Portable Heaters and Camping Equipment
- CPSC: Carbon Monoxide Information Center
- Mr. Heater: Warranty Policy (Buddy heater certification statement)
- Mr. Heater: MH4B Little Buddy Operating Instructions and Owner's Manual
- Mr. Heater: MH9BX Portable Buddy Heater (product page and Operating Instructions and Owner's Manual)
- Mr. Heater: Buddy FLEX Heater (product page and MH11BFLEX manual)
- CPSC: Mr. Heater Announce Recall to Repair Big Buddy/Tough Buddy Propane Heaters (2005)
- Mr. Heater: MH12HB Hunting Buddy Portable Heater
Common questions
What does indoor-safe mean on a propane heater?
On Mr. Heater's Buddy heaters it means the heater is certified for use in small enclosed spaces, such as fishing huts, cabins and tents, when you give it the fresh-air opening the manual requires. They have an oxygen depletion sensor and a tip-over shut-off. It does not mean you can close up the room, sleep with it on or skip a carbon monoxide alarm.
Can I sleep with a Buddy heater running?
No. Mr. Heater's manuals say never to operate the heater while sleeping, and the CPSC says not to use portable heaters while sleeping in enclosed areas such as tents and campers.
Can I use these heaters in Massachusetts or Canada?
Not the versions on this page. Mr. Heater sells separate Massachusetts and Canada versions that are labeled for outdoor use only. The models here are sold for the rest of the U.S.