OPINION
SCHULTE, Justice.This is an appeal from a judgment on a jury verdict in a workers’ compensation suit. The court awarded Appellee, Venita Courtney, death benefits as the widow of Bennie R. Courtney. The jury found that the deceased sustained a heart attack in the course of his employment which was a producing cause of his death. Appellant complains that the evidence was legally insufficient to establish that the fatal heart attack occurred in the course of decedent’s employment because there was no probative evidence that he experienced a particular strain, exertion, or other precipitating event while on the job. Alternatively, Appellant argues that the finding that the heart attack occurred in the course of the decedent’s employment was against the overwhelming weight and preponderance of the evidence and manifestly unjust. We affirm.
Mr. Courtney’s family had a history of heart attacks. Two brothers had died of heart attacks, one at the age of forty-two and one at fifty-four years of age. His father had died of a heart attack while in *383his sixties. Mr. Courtney, who was fifty-one years old at the time of his death, was granted disability by the Army in 1947 for acute rheumatic fever causing a mitral insufficiency. In August, 1980, Mr. Courtney passed out from heat exhaustion while at work. Prior to his heart attack, Mr. Courtney had not complained of having heart problems or chest pains, but had occasionally complained of feeling weak. He did indicate to one co-worker that he believed that he would ultimately die of a heart attack.
Employed as a welder’s helper by Phillips Petroleum Company, Mr. Courtney was a conscientious worker, and worried constantly that he might fail to correctly perform his work. On January 6, 1982, Mr. Courtney reported to work at a job site where his crew was repairing a leak in a twenty-four-inch pipe line. The crew members had been assembled at the job site for fifteen-to-twenty minutes when Mr. Courtney proceeded to the company truck to retrieve a buffer or grinder from the tool box. The top of the tool box was four feet off the ground and made of Vs inch sheet metal. The box was shoulder high to Mr. Courtney and its lid weighed approximately 2V2 pounds. Almost immediately after raising the tool box lid, Mr. Courtney collapsed. Up to that point, Mr. Courtney had not complained or shown any signs of feeling ill that morning.
Two medical experts testified. Dr. Connie Clifford Hutton, a thoracic cardiovascular surgeon, testified for Appellee, and Dr. Bryan D. Mohr, a specialist in cardiovascular medicine, testified for the Appellant. Both doctors agreed that Mr. Courtney had suffered a heart attack.
Dr. Hutton testified that any type of increased activity can cause a heart attack. According to Dr. Hutton, Mr. Courtney's family history and risk factors indicated a high probability of coronary disease and in such condition it was medically probable that lifting the tool box lid precipitated the heart attack. He also testified that worry can cause a great amount of physical stress for the body.
Dr. Mohr testified that although Mr. Courtney had sustained heart damage as a result of rheumatic fever, it was not a serious or debilitating condition and rheumatic heart disease did not contribute to his death. He also testified that Mr. Courtney’s fainting incident was not as serious as heat exhaustion or heat stroke, but was only heat induced fainting which did not cause any permanent damage. Dr. Mohr further stated that Mr. Courtney did have severe coronary artery disease which had developed over many years, but he believed that Mr. Courtney’s death was not related to his occupation because at the time the attack occurred, Mr. Courtney was not performing an activity which would put a strain on his heart. According to Dr. Mohr, raising the lid of a tool box could not precipitate a heart attack. On cross-examination, Dr. Mohr admitted that stress can precipitate, aggravate, or accelerate a heart attack and that the amount of stress necessary to trigger a heart attack was relative to the extent of the patient’s artery disease. He also indicated that the greatest risk factors for heart attack are age, male sex, hypertension, cholesterol level, use of tobacco and heredity.
Appellant challenges both the legal sufficiency and the factual sufficiency of the evidence to support the jury finding that Mr. Courtney’s fatal heart attack occurred in the course of his employment. In determining whether there is no evidence to support the jury finding, this Court must consider only the evidence and inferences which tend to support the jury finding and disregard all evidence and inferences to the contrary. Stodghill v. Texas Employers’ Insurance Association, 582 S.W.2d 102, 103 (Tex.1979); U.S. Fire Insurance Company v. Rearden, 695 S.W.2d 758, 760 (Tex.App.-El Paso, 1985, no writ). The evidence and inferences from the evidence supporting the jury verdict in this case are sufficient to withstand a no evidence challenge.
Where the sufficiency of the evidence is challenged, however, we must consider all the evidence in the case to determine if the *384finding is so contrary to the great weight and preponderance of the evidence as to be manifestly unjust. Garza v. Alviar, 395 S.W.2d 821, 823 (Tex.1965); Rearden, supra, at 761-62.
A heart attack caused by strain or overexertion is an accidental injury to the physical structure of the body within the meaning of the Workers’ Compensation Act. Henderson v. Travelers Insurance Company, 544 S.W.2d 649, 650-51 (Tex.1976); Baird v. Texas Employers ’ Insurance Association, 495 S.W.2d 207, 211 (Tex.1973). To recover, a claimant must establish that a particular event caused the heart attack. Brown v. Texas Employers’ Insurance Association, 635 S.W.2d 415, 416-17 (Tex.1982). The event must be traceable to a definite time, place and cause. Olson v. Hartford Accident and Indemnity Company, 477 S.W.2d 859, 860 (Tex.1972). The particular event which caused Mr. Courtney’s heart attack was lifting the tool box lid to remove his tools. The evidence is undisputed that the heart attack occurred almost immediately after this event. Although this task may not be looked upon as a great physical strain or exertion, the requisite strain or exertion may be less for someone suffering from a preexisting circulatory problem. Baird, supra; Continental Insurance Company v. Marshall, 506 S.W.2d 913 (Tex.Civ.App.-El Paso 1974, no writ); Texas Employers’ Insurance Association v. Brown, 622 S.W.2d 608 (Tex.Civ.App.-El Paso 1981) affirmed, 635 S.W.2d 415. In Baird, the decedent had climbed a five-foot ladder and helped lift a ten-to-twelve pound piece of aluminum conduit. Mr. Baird had previously been diagnosed as suffering from mild congestive heart failure and angina pectoris. A physician testified that based on reasonable medical certainty, the decedent’s exertions were the producing cause of his death. Baird, supra, at 208-210. The Supreme Court reversed an instructed verdict for the employer’s compensation carrier and remanded the case for a factual determination of whether the decedent had suffered an injury in the course of his employment and if so, whether such was a producing cause of his death. In Marshall, the decedent had previously suffered a heart attack and an episode of passing out from postural hypertension. He was employed by an oil company as a pump station operator. The events precipitating his heart attack were ascending nine concrete steps and possibly using force to open an oil control valve. A doctor testified that the decedent’s heart attack was most probably caused by these physical exertions. We affirmed the jury’s finding that the heart attack had occurred in the course of his employment and that it was a producing cause of his death.
Appellee’s case presents a similar situation. Both physicians testified that the decedent had preexisting heart problems. Although the strain experienced by Mr. Courtney may have been slight, Dr. Hutton’s testimony that lifting the tool box lid in medical probability caused the heart attack, supports the jury’s finding that the heart attack did occur in the course and scope of Mr. Courtney’s employment.
In considering an “insufficient evidence” point, we must remain cognizant of the fact that it is for the jury, as the trier of fact, to judge the credibility of the witnesses, to assign the weight to be given their testimony, and to resolve any conflicts or inconsistencies in the testimony. Taylor v. Lewis, 553 S.W.2d 153, 161 (Tex.Civ.App.—Amarillo 1977, writ ref’d n.r.e.). This court may not substitute its judgment for that of the jury if the challenged finding is supported by some evidence of probative value and is not against the great weight and preponderance of the evidence. Alford, Meroney & Co. v. Rowe, 619 S.W.2d 210, 213 (Tex.Civ.App.-Amarillo 1981, writ ref’d n.r.e.).
Commonwealth Lloyds’ Insurance Company v. Thomas, 678 S.W.2d 278, 289 (Tex.App.-Fort Worth 1984, writ ref’d n.r.e.). The Appellant’s points of error are overruled.
The judgment is affirmed.