This is a products liability case in which we are asked to review the propriety of summary judgments granted in favor of the defendants pursuant to GCR 1963, 117.3, and affirmed by the Court of Appeals.
*150I
This action was instituted by the plaintiff insurer-subrogee of Duane and Mary Geiger. When the Geigers purchased their home in 1975, it had a prefabricated sheet metal fireplace manufactured by defendant Heatilator Fireplace. The fireplace is known in the trade as a "zero-clearance” fireplace because there is no clearance between the fireplace and abutting combustible materials. The unit has two air vents, one at the base of the unit and the other at the top. Air is drawn into the unit through the base vent, circulates in a chamber which runs underneath and behind the unit, and exits from the vent at the top of the unit. The air which circulates through the chamber serves the purpose of warming the room into which it circulates. It also serves the purpose of keeping cool the outer wall of the chamber.
In 1979 the Geigers installed on the fireplace glass doors manufactured by defendant Hart Fireplace Furnaces. Shortly thereafter, the Geigers’ home caught fire. According to plaintiff’s expert, "[t]he cause of this fire was the overheating of the outer steel shell of the fireplace when the ventilation air slot at the front of the unit was inadvertently blocked by the insured’s installation of a set of glass fireplace doors. The elevated temperature of the outer steel shell of the fireplace eventually ignited adjacent combustible material.”
The plaintiff insurer paid the Geigers $65,000 for the property damage that they suffered as a result of the fire and instituted this action against Heatilator, later adding Hart. Plaintiff claimed, among other things, that the defendants were negligent in failing to provide proper warning to the Geigers that the airflow below the interior hearth should not be blocked because of the risk of *151fire it created. Heatilator moved for summary judgment and the trial court granted the motion based on Mr. Geiger’s deposition testimony that he knew that he was not to cover the fireplace’s air vents. The trial court explained:
The depositions of a number of people were taken in the . . . case and, I believe, there is no dispute about them, and in one of the depositions Mr. Geiger indicated that he knew that he should not cover the air vents and that he did not, in fact, cover the air vents.[1]
There is, however, an expert who says that the air vents were covered so it seems to me that the cause of action by Mr. Geiger as a subrogor of Michigan Mutual Insurance Company is left with Mr. Geiger’s position that he knew it and any effective warning would not have done any good, and so as a result I am inclined to feel that the motion for summary judgment should be granted and an order may be so entered.
Plaintiffs motion for reconsideration was denied, and Hart’s subsequent motion for summary judgment, adopting by reference Heatilator’s motion and briefs, was granted.
The Court of Appeals affirmed,2 holding that in addition to the risks being known by the plaintiff’s subrogors, defendants in this case had no duty to warn because the product involved was simple and the risks which it posed were obvious to all. Fisher v Johnson Milk Co, Inc, 383 Mich 158; 174 NW2d 752 (1970); Owens v Allis-Chalmers Corp, 414 Mich 413; 326 NW2d 372 (1982).
Plaintiff has filed an application for leave to appeal._
*152II
Plaintiff contends that the trial court and the Court of Appeals erred in assuming that because Mr. Geiger testified that he knew that air vents should not be blocked, he knew blocking them would create a fire hazard. An alternative inference is that he knew he should not have blocked the air vents because it would cause the fireplace to lose its special function of heating the room by circulating air through the unit. Under the circumstances, the courts were required to accept the latter inference favorable to the plaintiff. The Court of Appeals also erred by applying a "simple tool” analysis to this case because the Heatilator fireplace cannot be considered a simple tool and the risk of fire which it poses cannot be considered patent and obvious.
The defendants respond that the trial court and the Court of Appeals properly concluded that Mr. Geiger was aware of the risk involved in blocking the air vents of the furnace. In addition to the deposition testimony cited by the trial court, the defendants contend that the following testimony further establishes Mr. Geiger’s awareness that a fire might result from blocking of the air vents:
Q. Did you during this period of time understand how this type of fireplace worked, so far as preventing heat from going from the fireplace to the structure itself?
A. To the extent that it relied on airspace.
Q. Did you know that?
A. Yes.
Q. And did you know how air was circulated into the air space.
A. I thought through that slot in the lower section there.
*153According to the defendants, although Mr. Geiger did not specifically mention the word "fire,” his understanding that heat from the furnace unit would escape into the surrounding structure of his house if the air vents were blocked encompassed that possibility. Furthermore, the defendants contend that the Court of Appeals properly found that there was no duty to warn because the fireplace is a simple tool and the dangers involved in blocking the air are obvious.
Ill
Assuming without deciding that the defendants had a duty to warn of the dangers of covering the vents, our review leads us to conclude that the summary judgments were erroneously granted in this case. A pretrial motion for summary judgment pursuant to GCR 1963, 117.3 may not be granted unless the court, giving "the benefit of any reasonable doubt to the opposing party,” determimes that "there is no genuine issue as to any material fact.” Rizzo v Kretschmer, 389 Mich 363, 372; 207 NW2d 316 (1973). Giving every reasonable doubt to the plaintiff in this case, it cannot be concluded that Mr. Geiger was fully aware of the fire risk posed by obstruction of the unit’s air vents. While it is undisputed that Mr. Geiger was aware that the unit’s air vents should not be blocked, a reasonable inference favorable to the plaintiff is that he believed this would obstruct the airflow necessary for the fireplace to serve its room-heating purpose. Furthermore, while the testimony cited by the defendants indicates that Mr. Geiger was aware that the unit airflow served the function of preventing heat loss to the surrounding building structure, an inference unfavorable to the plaintiff would have to be drawn to conclude that Mr. *154Geiger was aware that obstruction of this function could cause a fire. Even if it is arguable that Mr. Geiger’s testimony establishes consciousness on his part of a vague danger, it would not preclude a jury from finding that a warning was nonetheless required to give him a full appreciation of the seriousness of the life-threatening risks involved. See Graham v Ryerson, 96 Mich App 480, 489; 292 NW2d 704 (1980).
The Court of Appeals "simple tool” analysis based on this Court’s decisions in Fisher v Johnson Milk Co, Inc, supra, and Owens v Allis-Chalmers Corp, supra, is inappropriate. This is not a case involving an obvious or patent danger or, for that matter, a simple tool. We are persuaded that it is not at all obvious that blocking the air vents on a fireplace of this type will cause the outer walls of the fireplace to overheat to the point of igniting surrounding materials.
The trial court ruling indicates that the court may also have granted the motions for summary judgment on the ground that failure to warn of risk of fire could not have been a proximate cause of the fire because Mr. Geiger was already aware that he should not block the air vents. This rationale, however, is erroneous. The fact that Mr. Geiger was aware that he should not block the opening of the air vents does not mean that a warning concerning the risk of fire would have had no effect. Notice of the risk of fire, with its threat to life, arguably would have motivated Mr. Geiger to take more care to ensure that the vents were not obstructed and would have led him to discover that the glass doors were in fact obstructing the vent opening.
Accordingly, in lieu of granting leave to appeal, pursuant to MCR 7.302(F)(1), we reverse the judgment of the Court of Appeals and of the Kent *155Circuit Court and remand the case to the Kent Circuit Court for trial.
Williams, C.J., and Ryan, Brickley, Cavanagh, Boyle, and Riley, JJ., concurred.Specifically, Mr. Geiger testified, "I don’t feel it was blocked. In my opinion, I wouldn’t have blocked it, knowing that it needed an air space, when I built the hearth.”
126 Mich App 837; 338 NW2d 238 (1983).