Plaintiffs, Merlon and Guelda Frey, commenced this action to recover damages allegedly caused by overheating from a space heater purchased from defendant, Montgomery Ward & Company, Inc. (Montgomery Ward), for use in a house trailer where plaintiffs bred and raised chinchillas for commercial purposes. Montgomery Ward then commenced a third-party action against McGraw-Edison Company (McGraw-Edison), manufacturer of the space heater, and Mc-Graw-Edison impleaded Robertshaw Controls Company (Robertshaw), manufacturer of the space heater control unit, as a fourth-party defendant.
Before the case went to the jury, the trial court granted a motion for a directed verdict in favor of McGraw-Edison, and a motion for dismissal in favor of Robertshaw, in addition to directing a verdict against Montgomery Ward on the issue of its negligence. The jury by special verdict found plaintiffs had been damaged in the amount of $28,000 and Montgomery Ward has appealed from the entry of judgment and *785from the denial of its alternative motions for judgment notwithstanding the verdict or for a new trial. We affirm in part, reverse in part, and remand.
On March 24, 1971, plaintiffs purchased a gas space heater which was on display as a floor model at the Montgomery Ward retail store in St. Paul. The space heater had been manufactured by McGraw-Edison and sold to Montgomery Ward for resale under it own label. Although the clerk who made the sale had no recollection of Frey or of the particular transaction, Frey testified that he had told the clerk of his intended use of the space heater in a house trailer where he planned to raise chinchillas for breeding and pelting purposes.
Frey took the space heater to the Salvation Army Camp on Silver Lake, in New Brighton, where he lived and worked as caretaker and maintenance man. Frey installed the space heater and vented it himself, using his own gas line and regulator connected to a supply of bottled gas. After completing the installation, Frey asked a Skelgas serviceman to inspect it and determine if the space heater had been correctly installed and was working properly.
Until February 8, 1972, the space heater operated satisfactorily, automatically maintaining the temperature in the trailer between 68 and 70 degrees. On the evening of February 7, before Mrs. Frey went to bed, she made her regular nightly visit to check on the herd of 360 chinchillas located in pens in the trailer house. The outside temperature was not unusually cold and since the temperature in the trailer was within the proper range, Mrs. Frey made no adjustment of the space heater’s thermostatic control.
The next morning at 9:00 a. m., when Frey went out to the trailer, he found the temperature inside was over 110 degrees. The chinchillas in the top layer of cages, near the ceiling, were already dead and those in the cages beneath were dead or dying. Frey turned off the space heater and attempted to cool the trailer by opening the windows and doors.
Mrs. Frey called Montgomery Ward and they dispatched serviceman William O’Ka-sick. When he arrived, he was unable to observe any defect in the heat control unit or to ascertain whether it was operating automatically since the temperature in the trailer had dropped to less than 50 degrees. Because the space heater was still under warranty, O’Kasick replaced the Robert-shaw heat control unit with one from a different manufacturer, tagged the control unit he had removed, and turned it in to Montgomery Ward’s defective parts station. Montgomery Ward then returned the control unit to McGraw-Edison pursuant to a vendor charge-back procedure, but the control unit was misplaced by McGraw-Edison before plaintiffs commenced this action.
After installation of the new heat control unit, the space heater still failed to operate automatically and Frey stayed in the trailer that evening to manually adjust the heat in order to maintain the proper temperature. Shortly thereafter, a Skelgas serviceman replaced the gas line and a secondary regulator leading from the bottled gas tank because of low pressure at the burner, and O’Kasick returned to replace the heat sensor on the newly installed heat control unit. From that time on the space heater operated properly.
Frey testified that although only 32 chinchillas had died on the morning of February 8, the animals continued to get sick and die, making it necessary to dispose of 330 of them. Leroy Long, former field representative for two chinchilla promotion companies, testified that he had seen plaintiffs’ rare and unusual chinchilla herd the day before the overheating occurred and that the herd had been in excellent condition. He stated that chinchillas have no tolerance for heat and become sterile or die as a result of high temperatures.
Robert Knudson, former director of engineering for heating products at McGraw-Edison, testified that in his opinion the space heater had not malfunctioned at all but rather the overheating was caused by stratification of air in the trailer, with hot air rising to the ceiling and cold air remain*786ing below in contact with the heat sensor. Knudson stated that McGraw-Edison’s space heaters were not designed for use in house trailers which have inadequate insulation and that if so utilized the space heater’s open combustion system could be dangerous by reason of the excessive utilization of oxygen within a tightly enclosed area.
Although McGraw-Edison furnished an owner’s guide and venting instructions for use with its space heaters which contained specifications and recommendations for installation and operation, these printed booklets did not state that the space heaters should not be used in house trailers or in other poorly insulated and tightly enclosed spaces.
Before final arguments, the trial court granted McGraw-Edison’s motion for directed verdict and Robertshaw’s motion for dismissal, dismissing them from the action on grounds that there was no evidence to establish that the space heater was defectively manufactured or that it would have malfunctioned if properly used, i. e., not used in a house trailer. At the same time the trial court directed a verdict against Montgomery Ward on the issue of negligence because of its sale of the space heater for use in plaintiffs’ house trailer, but the court asked the jury to determine whether Montgomery Ward’s negligence was the proximate cause of the damages alleged by plaintiffs. The jury found by special verdict that Montgomery Ward was 100 percent negligent and that plaintiffs had been damaged in the amount of $28,000.
1. Montgomery Ward contends that the trial court committed error by directing a verdict on the issue of its negligence in the sale of the space heater to plaintiffs to be used in plaintiffs’ house trailer.
Frey testified that he told the Montgomery Ward salesperson of his intended placement of the space heater in the house trailer where he planned to raise chinchillas and that the salesperson gave no indication that such use would be unsuitable or dangerous. We have held that in any determination of whether equipment furnished for a specific purpose is safe, the circumstances for which it is to be used are to be considered in ascertaining the negligence of the seller. Where the seller has knowledge of the particular conditions under which the equipment is to be used, knowledge of dangers which are inherent in such use may be imputed to the seller. Manteuffel v. Theo. Hamm Brewing Co., 238 Minn. 140, 56 N.W.2d 310 (1952).
Further, when the seller knows or should anticipate that an inexperienced purchaser might use the item sold in a particular manner, the seller has a duty to warn of any dangers which might arise from that use if the seller knows or should realize that it is likely to be dangerous for such use and has no reason to believe that the purchaser will comprehend the danger. Clark v. Rental Equipment Co. Inc., 300 Minn. 420, 220 N.W.2d 507 (1974).
Knudson’s testimony established that the space heater sold to plaintiffs was an open combustion system, operating by gravity, and its use in a poorly insulated area could result in air stratification. Knudson stated that the space heater was inappropriate for use in such an area and was not manufactured for that purpose because of the inherent dangers of overheating and asphyxiation.
Although the uncontradicted testimony of a witness may be disregarded where such testimony has been impeached or made improbable by reasonable inferences drawn from the evidentiary facts, Knudson’s testimony could not be arbitrarily ignored by the trial court in the absence of any inconsistent or contradictory evidence. Nelson v. Ackerman, 249 Minn. 582, 83 N.W.2d 500 (1957); O’Leary v. Wangensteen, 175 Minn. 368, 221 N.W. 430 (1928).
The trial court may direct a verdict for the party in whose favor the evidence overwhelmingly preponderates even though there is some evidence in favor of the adverse party. J. N. Sullivan & Assoc. v. F. D. Chapman Const. Co., 304 Minn. 334, 231 N.W.2d 87 (1975). The evidence in the instant case was sufficient to establish *787Montgomery Ward’s duty to warn plaintiffs against improper use of the space heater in their house trailer, and the evidence was also sufficient to establish a breach of that duty based upon Montgomery Ward’s imputed knowledge of the danger of such use. Therefore, the directed verdict was not error considering its limitation by the trial court solely to the issue of Montgomery Ward’s negligence.
2. Montgomery Ward also contends that the evidence did not establish that the space heater caused the death of plaintiffs’ chinchillas. By directing a verdict solely on the issue of negligence, the trial court properly left to the jury the determination of whether Montgomery Ward’s negligent act was the proximate cause of plaintiffs’ damages. Negligence and proximate cause are separate factors in assigning tort liability and the question of proximate cause is normally one for the jury to decide. Vanderweyst v. Langford, 303 Minn. 575, 228 N.W.2d 271 (1975).
Leroy Long, plaintiffs’ expert witness, testified that chinchillas have no tolerance for heat and will die or become sterile as a result of high temperatures. Moreover, Long stated that he had seen plaintiffs’ chinchilla herd on February 7, the day before the space heater overheated, and that the animals were in excellent condition. Frey gave testimony that 32 chinchillas had died on February 8 and that subsequently approximately 300 other chinchillas had died or become sick, making it necessary to dispose of them.
Because of the unique and unusual business of raising chinchillas on a commercial basis, the jury could properly take into consideration the experience and knowledge of plaintiffs’ expert in determining the cause of the chinchillas’ deaths. Moreover, Montgomery Ward offered no evidence to refute this testimony or to establish any other possible cause of the loss of the chinchillas.
The decision of a jury on the question of proximate cause and damages will not be set aside unless it is manifestly contrary to the evidence viewed as a whole in the light most favorable to the verdict. Vanderweyst v. Langford, supra. Here, the evidence was sufficient to support the jury’s determination that plaintiffs’ damages were proximately caused by Montgomery Ward’s sale of the space heater and the subsequent overheating of the trailer.
3. Although Montgomery Ward does not take issue with the trial court’s dismissal of Robertshaw, it contends that the trial court should not have directed a verdict for McGraw-Edison. Montgomery Ward argues that if it was negligent as a matter of law, then McGraw-Edison was similarly negligent by reason of its failure to include in the printed venting instruction booklet or owner’s guide any warning that the space heater should not be used in a house trailer or other poorly insulated or tightly enclosed area.
It is clear from the record that McGraw-Edison had actual knowledge that its space heater, when used under such circumstances, could give rise to inherent dangers, since its own expert witness testified that the space heater, which utilizes an open combustion system, was unsafe for use in a mobile home or trailer because of the possibilities of overheating or asphyxiation.
The owner’s guide and venting instructions were prepared by McGraw-Edison and approved by Montgomery Ward. The testimony revealed that use of the space heater in mobile homes and other tightly enclosed areas was not approved by the American Gas Association and that such use would be ill-advised and potentially dangerous. However, no warning of the inherent dangers of such use was set forth in the instruction booklet or owner’s guide.
The duty to warn has been described as two duties: (1) The duty to give adequate instructions for safe use; and (2) the duty to warn of dangers inherent in improper usage. The distinction between the giving of adequate instructions for effective use and the giving of an adequate warning of potential danger to assure safe use is explained in 1 Frumer and Friedman, Products Liability, § 8.05(1), which states:
*788“ * * * It is clear from the better-reasoned cases that directions for use, which merely tell how to use the product, and which do not say anything about the danger of foreseeable misuse, do not necessarily satisfy the duty to warn.”
We have held that where the manufacturer or the seller of a product has actual or constructive knowledge of danger to users, the seller or manufacturer has a duty to give warning of such dangers. Hill v. Wilmington Chemical Corp., 279 Minn. 336, 156 N.W.2d 898 (1968); Annotation, 76 A.L.R.2d 9. As we stated in Lovejoy v. Minneapolis-Moline Power Implement Co., 248 Minn. 319, 325, 79 N.W.2d 688, 693 (1956):
“ * * * If the manufacturer undertakes by printed instructions to advise of the proper use to be made of a chattel, he assumes the responsibility of giving accurate and adequate instructions with respect to the dangers inherent in its use in some other manner.”
See, Johnson v. West Fargo Manufacturing Co., 255 Minn. 19, 95 N.W.2d 497 (1959); Hartmon v. National Heater Co., 240 Minn. 264, 60 N.W.2d 804 (1953).
This court distinguished between operational instructions and warnings of inherent danger in the use of a chattel in Westerberg v. School District No. 792, 276 Minn. 1, 148 N.W.2d 312 (1967), but recognized the necessity of a limitation on the manufacturer’s duty to warn and on the manufacturer’s liability in the retail sale of his products. We held that the manufacturer’s duty to warn must rest on foreseeability, with no duty to warn of an improper use that could not have been foreseen.
The owner’s guide and the venting instruction booklet supplied by McGraw-Edi-son with its space heaters gave adequate directions for proper and effective use. However, the booklets had no warning to assure safe use or to caution of the dangers of misuse by placement of the space heaters in house trailers or in other small, tightly enclosed or poorly insulated areas.
Whether McGraw-Edison reasonably could have foreseen or anticipated the use of its space heaters in house trailers and thus whether the risk for which there was no warning was a reasonably foreseeable one was properly a jury question. By directing a verdict in favor of McGraw-Edison, the trial court took from the jury the right to determine this question. A trial court is not justified in directing a verdict if different minds, applying the legal criteria of due care, might reasonably arrive at different conclusions. Stenzel v. Bach, 295 Minn. 257, 203 N.W.2d 819 (1973). Thus, the question of McGraw-Edison’s duty to warn must be remanded for a new trial.
If McGraw-Edison is therein found to have acted without due care, the question of the proper allocation of liability between McGraw-Edison and Montgomery Ward arises. In Hendrickson v. Minnesota Power & Light Co., 258 Minn. 368, 372, 104 N.W.2d 843, 848 (1960), we reviewed our decisions concerning indemnity between joint tort-feasors and adopted the following rules:
“ * * * A joint tortfeasor may generally recover indemnity only in the following situations:
“(1) Where the one seeking indemnity has only a derivative or vicarious liability for damage caused by the one sought to be charged.
“(2) Where the one seeking indemnity has incurred liability by action at the direction, in the interest of, and in reliance upon the one sought to be charged.
“(3) Where the one seeking indemnity has incurred liability because of a breach of duty owed to him by the one sought to be charged.
“(4) Where the one seeking indemnity has incurred liability merely because of failure, even though negligent, to discover or prevent the misconduct of the one sought to be charged.
“(5) Where there is an express contract between the parties containing an explicit undertaking to reimburse for liability of the character involved.”
We leave it to the trial court to determine whether the instant case falls within Rule 3, as suggested by Mr. Justice Kelly in his concurring opinion, or whether it falls *789within Rule 4. If found to be a Rule 4 situation, then we direct the attention of the court below to our recent decision in Tolbert v. Gerber Industries, Inc., Minn., 255 N.W.2d 362 (1977).
We affirm the judgment as to the dismissal of the claim against Robertshaw, the directed verdict against Montgomery Ward on the issue of negligence, and the award of damages to plaintiffs. However, the directed verdict in favor of McGraw-Edison is reversed and remanded for a new trial.
Affirmed in part, reversed in part, and remanded.