This is an appeal from an order of the district court requiring officials at the South Dakota State Penitentiary (SDSP) to cease double celling inmates at SDSP, both in the general population and in protective custody. On appeal, the officials contend that the trial court erred in finding that double-celling inmates at SDSP violates the Eighth and Fourteenth Amendments to the United States Constitution. They also claim the court erred in using the “rated capacities” of the American Corrections Association as a referrent for measuring constitutional violations. Protective custody inmates cross-appeal claiming that they are treated differently from inmates in the general population in violation of equal protection guarantees. We affirm.
BACKGROUND
William R. Cody filed this class action suit under 42 U.S.C. § 1983 on behalf of all persons who are now or will be incarcerated in the South Dakota State Penitentiary at Sioux Falls, South Dakota or in the Women’s Correctional Facility at Yankton, South Dakota. Cody complained of overcrowding and living conditions hazardous *449to the health of the inmates. He protested, among other things, poor medical care, inadequate recreation, contaminated food, and noncompliance with fire safety standards. After an eleven day trial, the district court found that many of these conditions violated the eighth and fourteenth amendments to the United States Constitution. The trial court ordered the prison officials to prepare plans to cure the constitutional violations, which prison officials submitted by the summer of 1985. After extensive negotiation, the parties entered into a consent decree covering certain improvements to be made at the SDSP.
Following a hearing on July 8, 1985, the trial court entered the partial consent decree, and a second judgment on the remaining contested issues, which is the subject of this appeal. It ordered: 1) That except in the case of certain emergencies, the daily population of the SDSP be reduced in compliance with a schedule aimed at reducing the population to 95% of that specified by the American Corrections Association (ACA) as the capacity of SDSP; 2) that SDSP will stop double-celling inmates in protective custody; and 3) further improvements in health services. The state appeals orders one and two which concern double-celling.
On appeal, the officials claim that they have already ended the practice of double-celling general population inmates and have greatly reduced the double-celling of protective custody inmates, but they do not believe this is required by the Constitution, and they want to retain the flexibility to double-cell, if necessary, in the future. They also claim that the district court erred in requiring them to comply with American Correctional Association guidelines for setting prison population máximums.
DISCUSSION
The Eighth Amendment to the United States Constitution prohibits cruel and unusual punishment. In Rhodes v. Chapman, 452 U.S. 337, 101 S.Ct. 2392, 69 L.Ed.2d 59 (1981), the Supreme Court considered for the first time the limitation that the eighth amendment imposes upon the conditions in which a state may confine those convicted of crimes. The Court stated that conditions of confinement “must not involve the wanton and unnecessary infliction of pain, nor may they be grossly disproportionate to the severity of the crime warranting imprisonment.” Rhodes, 452 U.S. at 347, 101 S.Ct. at 2399.
The Rhodes Court specifically considered whether double-celling at an Ohio prison constituted cruel and unusual punishment. The Court held that in light of the otherwise exceptionally good conditions of confinement at the institution,1 doublecelling was not unconstitutional because it “did not lead to deprivations of essential food, medical care, or sanitation. Nor did it increase violence among inmates or create other conditions intolerable for prison confinement.” Rhodes, 452 U.S. at 348, 101 S.Ct. at 2400. Thus, in determining whether prison conditions such as doublecelling violate the eighth amendment, courts must consider all of the circumstances surrounding the conditions of confinement.
Applying this test, we affirm the district court’s holding that SDSP’s practice of double-celling, in light of the numerous deficient conditions of confinement at the prison, constitutes a violation of the eighth amendment under Rhodes. We point out that the prison officials did not appeal from the district court’s detailed findings of deficient conditions at SDSP. Accordingly, in assessing SDSP’s appeal of the double-celling orders, we accept as true *450the district court’s findings as to the conditions at SDSP.
At the time of trial, the SDSP housed 538 general population inmates in 440 single occupancy cells. One hundred and ninety-six inmates were doubled up. The cells ranged in size from fifty-five square feet to sixty-three square feet. Some of the cells lacked adequate ventilation, and other cells lacked running hot water. The electrical wiring in the cells is substandard.
The court found that fire safety measures are inadequate: exit doors insufficient, night staff insufficient to respond in an emergency, ventilation inadequate, no fire alarm system, sprinkling system, or automatic unlocking device for the cells doors, and that there were plastic pipes throughout the prison with the potential to emit toxic vapors during a fire. The court further found that kitchen conditions are unsanitary and unsafe, including an inadequate milk pastuerization procedure, improper storage of canned goods and un-cleanable dishes and pots. Additionally, medical and dental care available to prisoners is grossly inadequate. The medical and dental units are understaffed, and SDSP resorts to the use of untrained inmates to examine and x-ray patients.
The district court also made findings as to the impact of double-celling on the inmates, which SDSP officials again have not appealed from. The court found that:
Double-celling at the SDSP has resulted in crisis management with respect to the maintenance of ancillary support facilities such as food services, laundry services, medical services, plumbing and electrical wiring.
Double-celling at the SDSP has resulted in an overloading of services such as the work, recreation and school programs.
Since the advent of double-celling in the first part of 1981, there has been one recorded instance of a riot involving approximately twenty persons in November, 1981, and approximately sixty incidents * * * of fighting or assaults between inmates and/or inmates and staff.
The SDSP is grossly under-staffed. The level of prison staff has not increased in proportion to the level of the general inmate population.
Cody v. Hillard, 599 F.Supp. 1025, 1033 (D.S.D.1984).
Moreover, the court found that double-celling creates a serious potential for the spread of communicable diseases due to cramped living spaces and an increased potential for inmates to contact upper respiratory diseases.
We now turn to the district court’s findings with respect to protective custody inmates. Out of forty-five inmates housed in protective custody at the SDSP, twenty-two were double-celled. The district court found that “[t]he negative impact attributed to double-celling in other areas of the institution is exacerbated in the protective custody area due to the inordinately limited out-of-cell time available to these inmates.” Cody, 599 F.Supp. at 1034.
In light of the uncontested findings of fact that we have summarized, we conclude that the district court did not err in banning double-celling both in the general population and in protective custody cells. The facts found serve as an adequate basis to constitutionally require more space for inmates, not only to improve the health and safety conditions for the inmates, but to enhance security and to reduce violence. Our finding is supported by numerous decisions holding double-celling unconstitutional where there are other serious deficiencies in the conditions of confinement. See e.g., French v. Owens, 777 F.2d 1250, 1252 (7th Cir.1985), (Seventh Circuit upheld a ban on double-celling “in light of the poor supervision, safety, medical care and food preparation at the facility[.]”); Toussaint v. Yockey, 722 F.2d 1490, 1492 (9th Cir.1984) (injunction upheld against double-celling where it “engenders violence, tension and psychological problems”); Wellman v. Faulkner, 715 F.2d 269 (7th Cir.1983), cert. denied, 468 U.S. 1217, 104 S.Ct. 3587, 82 L.Ed.2d 885 (1984) (overcrowding can violate eighth amendment).
*451The SDSP, like the institutions at issue in French, Toussaint, and Wellman, is very different from the prison under scrutiny in Rhodes. It is anything but “a top flight institution,” and the horrible conditions are greatly exacerbated by double-celling of inmates.
In so holding, we do not intimate that the order banning double-celling cannot be modified in the future. Prison officials apparently have submitted progress reports — which are not part of the record on this appeal — alleging that improvements have been made at the SDSP. Prison officials should apply to the district court for an evidentiary hearing to determine the extent of the improvements. Upon a proper showing, the district court may determine that the ban on double-celling is no longer justified.
Finally, the state attacks the district court’s use of the ACA standards for prison capacity as the guidelines for constitutional requirements. It is true that Rhodes v. Chapman, suggested that district courts refrain from overreliance on expert opinions on prison capacity. However, the Court did not prohibit such consideration and several post-Rhodes decisions have approved the use of such guidelines as the ACA guidelines where the conclusions therein are supported by other independent evidence. See e.g., Touissaint, 722 F.2d 1490 (9th Cir.1984). The district court’s use of these guidelines is appropriate in light of its detailed factual findings, based on a wide-range of evidence.
The final issue on appeal is the cross-appeal by the protective custody inmates. They claim that the ban on doublecelling is not enough and that they are entitled to additional relief such as more exercise time. Their argument essentially is that conditions in the protective custody unit are not as good as conditions in the general population units and that this violates their rights to equal protection. We have previously stated that “[t]o succeed on an equal protection claim the [protective custody inmates are] required to show that they received treatment which was invidiously dissimilar to that received by other inmates.” Lyon v. Farrier, 730 F.2d 525, 527 (8th Cir.1984). We conclude that the cross-appellants have made no such showing.
. The physical plant, built in the early 1970s, was "unquestionably a top-flight, first-class facility.” Rhodes, 452 U.S. at 341, 101 S.Ct. at 2396. The cells there averaged sixty-three square feet and contained a cabinet-type night stand, a shelf and radio built into the wall, a wall-mounted sink with hot and cold running water and a flush toilet. All cells had a heating and air circulation vent near the ceiling and more than half of them had a window that the inmates could open and close. All cells used to house two inmates were equipped with two-tiered bunk beds. Medical, food and other services were good.