                               In the

 United States Court of Appeals
                For the Seventh Circuit

No. 12-2616

P ATRICIA F ERRARO ,
                                                  Plaintiff-Appellant,
                                   v.

H EWLETT-P ACKARD C OMPANY,
                                                  Defendant-Appellee.


              Appeal from the United States District Court
         for the Northern District of Illinois, Eastern Division
               No. 08 C 3638—Edmund E. Chang, Judge.



       A RGUED JANUARY 24, 2013—D ECIDED JULY 3, 2013




 Before M ANION and W OOD , Circuit Judges, and B ARKER,
District Judge.
  W OOD , Circuit Judge. Patricia Ferraro suffered serious
burns on her arm after falling asleep next to the power
adapter of her newly purchased Hewlett-Packard (HP)




  The Honorable Sarah Evans Barker, Judge of the United
States District Court for the Southern District of Indiana, sitting
by designation.
2                                              No. 12-2616

laptop computer. She filed a product liability suit against
HP, alleging that her injury resulted from a design defect
that allowed the power adapter to overheat. She also
claimed that HP failed to include adequate warnings
about the power adapter’s propensity to overheat and
that HP breached an implied warranty of merchantability.
At the close of discovery, HP moved for summary judg-
ment, which the district court granted in full.
   The court concluded that Ferraro would be unable
to show that the power adapter was “unreasonably danger-
ous,” a required element of her design defect claim.
Under Illinois law, there are two alternative methods
of establishing that element: the “consumer-expectations
test” or the “risk-utility test.” The district court found
Ferraro’s evidence insufficient to meet her burden under
either one of them. On appeal, Ferraro argues that the
district court erred only in concluding that she would be
unable to prove unreasonable dangerousness under the
consumer-expectations test. She has not challenged the
district court’s determination that HP was entitled to
summary judgment under the risk-utility test, nor has she
appealed the district court’s dismissal of her defective
warning and implied warranty claims. This puts her in
an impossible bind. Under Illinois law, the risk-utility
test “trumps” in design defect cases if the two methods
of establishing unreasonable dangerousness yield con-
flicting results. Because the district court’s finding that
she could not succeed under the risk-utility test
furnished an independent and unchallenged ground
for the decision, we affirm.
No. 12-2616                                              3

                             I
  In May 2006, Ferraro purchased a new HP DV800
Notebook laptop from a local Best Buy store. One week
later, while sitting on her sofa and using her laptop, she
noticed that the battery was running low. Ferraro shut
down the laptop, placed it on a nearby coffee table, and
plugged the laptop’s power cord into the wall. Midway
along the cord is the power adapter, a brick-shaped
plastic device housing a transformer, which converts AC
electricity from the outlet into DC electricity used by
the laptop. Ferraro propped the power adapter on the
arm of her sofa, began reading a book, and fell asleep
around 10:00 p.m.
  At some point during the night, the power adapter
slipped from the sofa’s arm, falling between the cushions.
As Ferraro slept, the exposed skin of her right forearm
came to rest against one of the adapter’s surfaces. It is
unclear how long Ferraro’s skin was in direct contact
with the adapter, but she eventually awoke with painful
blisters at the point of contact. Ferraro treated the
burn with cold water and wrapped her arm with gauze,
but she was unable to fall back asleep because of the
pain. Ferraro, a Chicago police officer, reported to work
early the next morning. She received some medical at-
tention at a fire station while patrolling her beat and
went to an emergency room at 3:00 p.m. once her shift
ended. Doctors diagnosed her with second- and third-
degree burns.
 Ferraro filed suit against HP (and against Best Buy,
which is no longer part of this dispute) in 2008, asserting
4                                              No. 12-2616

claims based on strict product liability and implied war-
ranty of merchantability. For purposes of her strict
product liability theory, she alleged that the laptop was
defectively designed because it “overheat[ed] during
normal and foreseeable use” and that it lacked “adequate
or sufficient warnings.” During discovery, each side
presented three expert witnesses, whose proffered testi-
mony we now summarize.
  Ferraro’s first expert was Peter Poczynok, a mechanical
engineer and litigation consultant. After reviewing the
power adapter, HP manuals, and deposition transcripts,
Poczynok concluded that HP should have included
additional warnings with the laptop or the adapter and
that HP should have designed the adapter differently to
reduce the amount of heat it generated. He suggested
that the transformer could have been housed inside the
laptop itself, as opposed to inside the external power
adapter; that the adapter could have included a built-in
fan to help vent heat; that the adapter could have been
manufactured with a “heat shield”; and that the box
housing the adapter could have been larger to allow
for greater air circulation.
   Nathaniel Johnson, an electrical engineer who mea-
sured the heat generated by the power adapter under
various conditions, was Ferraro’s second expert. Johnson
first took the power adapter’s temperature when it
was operating on a flat tabletop surface; the adapter
reached a temperature of 58.5 degrees Celsius (137.3
degrees Fahrenheit) after 90 minutes. Johnson then
covered the top of the adapter with a cotton towel, and the
No. 12-2616                                               5

temperature rose to 77.2 / C (170.96 °F). Johnson opined
that these temperatures posed severe burn risks, par-
ticularly since it is common practice for consumers to
use laptop computers in bed or on a couch, where
airflow around the power adapter might be restricted.
He suggested that the six-foot power cord connecting
the power adapter to the wall outlet could have been
shortened (and that the segment linking the power
adapter to the computer could have been lengthened
by a corresponding amount), reducing the likelihood
that a user would come into contact with the power
adapter.
  Finally, Dr. Robert Cucin, a doctor with board certifica-
tions in general surgery and plastic surgery, testified
about burn injuries. Cucin explained that skin will burn
after 50 minutes of direct contact with a surface that is
50 / C (122 °F). He also said that people sometimes incor-
porate “pain into their dreams and may not wake up
from it right away,” citing examples of persons burned
by sleeping pads.
  HP’s three experts challenged many of these conclu-
sions. Dr. Raphael Lee, a board-certified surgeon specializ-
ing in plastic surgery and burn care, testified that skin
temperature of 46 / C (114.8 °F) is associated with severe
pain and 52 / C (125.6 °F) is associated with second-
degree burns. He concluded that, “under normal phys-
iological conditions,” an individual whose skin is
in contact with a power adapter like the one at issue
here would feel severe pain within minutes and that
“normal involuntary spinal reflexes would cause with-
6                                               No. 12-2616

drawal of the skin from the source of the pain in a
matter of seconds.” Don Galler, an electrical engineer,
testified that the HP power adapter was compliant with
the relevant “international standard for safety,” which
dictates a “maximum allowable temperature” of 95 / C
(203 °F). Galler inferred, based on this relatively high
temperature, that the industry standard does not contem-
plate continuous contact between the product and a
consumer’s skin. Finally, Raina Shah, a human factors
engineer and consultant, testified that HP was not
required to provide users with additional warnings,
given the international standard and the absence of
similar warnings on the power adapters of most other
manufacturers’ laptops. She explained that the device
was designed to be placed on a flat surface (i.e., the floor
or a desk); that an ordinary user would cease contact
before suffering any burns in the event of inadvertent
contact; and that there was no history of severe burns
associated with the HP laptop power adapter.
  At the close of discovery, HP moved for summary
judgment on all claims. To defeat the motion on her
design defect claim, Ferraro needed to introduce evi-
dence that would have supported a finding (among
other things) that the power adapter was “unreasonably
dangerous.” She could do so through one of two ap-
proaches: the consumer-expectations test or the risk-utility
test. Under the consumer-expectations test, a plaintiff
may show unreasonable dangerousness by demon-
strating that the product “failed to perform as safely as
an ordinary consumer would expect when used in an
intended or reasonably foreseeable manner.” Lamkin v.
No. 12-2616                                                7

Towner, 563 N.E.2d 449, 457 (Ill. 1990). The district court
concluded that no reasonable jury could find “unreason-
able dangerousness” under this approach, since “fall[ing]
asleep while using the computer . . . is not the intended
use of a power adapter (powering the laptop and charging
its battery), nor a use that is foreseeably similar to its
intended use.” The court allowed the possibility that
Ferraro was making “the more limited argument that
an ordinary consumer would expect that the power
adapter would not get so hot that it would instantaneously
cause a burn,” but it explained that there was no evi-
dence that this is what happened. Accordingly, the
court concluded that “HP is entitled to summary judg-
ment on the consumer-expectations liability-theory
because no reasonable jury could find that the power
adapter was unreasonably dangerous for its intended
(or foreseeably similar) use.”
  In the alternative, the district court rejected Ferraro’s
argument that her evidence could establish “unreasonable
dangerousness” under the risk-utility test. The risk-utility
test requires a plaintiff to show that “the risk of danger
inherent in the design of the product outweighs the
benefits of the design.” Sobczak v. General Motors Corp., 871
N.E.2d 82, 92 (Ill. App. Ct. 2007); Calles v. Scripto-Tokai
Corp., 864 N.E.2d 249, 257-63 (Ill. 2007). Illinois courts
consider a broad range of factors in their risk-utility
analysis, including the magnitude and probability of the
foreseeable risks of harm; the instructions and warnings
accompanying the product; the nature and strength of
consumer expectations regarding the product, including
expectations arising from product portrayal and market-
8                                                No. 12-2616

ing; the likely effects of any alternative designs on pro-
duction costs; and conformity with industry standards,
voluntary organization guidelines, and government
regulation. See Mikolajczyk v. Ford Motor Co., 901 N.E.2d
329, 335 (Ill. 2008); Jablonski v. Ford Motor Co., 955 N.E.2d
1138, 1154 (Ill. 2011). The district court considered
several of these factors, concluded that none tipped
in Ferraro’s favor, and held that “no reasonable jury
could find for Ferraro (who bears the burden of proof)
under the risk-utility test.”
  Finally, the district court rejected Ferraro’s arguments
that the power adapter was defective because it lacked
adequate warnings and that HP breached an implied
warranty of merchantability. Ferraro’s failure-to-warn
theory was unavailing, the district court reasoned,
because there was no evidence that HP had special knowl-
edge of the adapter’s propensity to burn consumers or
that the burn danger was non-obvious. See Sollami v.
Eaton, 722 N.E.2d 215, 219 (Ill. 2002). The implied-warranty
claim failed because it “require[d] a showing that the
goods were . . . unfit for the ordinary purposes for which
the goods are used,” see Maldonado v. Creative Wood-
working Concepts, Inc., 342 Ill. App. 3d 1028, 1034 (Ill. App.
Ct. 2003), and the court thought that Ferraro “d[id] not
allege, let alone provide evidence, that HP’s power
adapter was unfit in fulfilling [its] purposes [of]
provid[ing] power to the laptop and . . . charg[ing] the
laptop battery.” Accordingly, the court granted HP’s
motion for summary judgment and dismissed the case.
No. 12-2616                                               9

                             II
  In reviewing the grant of a motion for summary judg-
ment, we construe the facts and draw all reasonable
inferences in favor of the nonmoving party. Sojka v. Bovis
Lend Lease, Inc., 686 F.3d 394, 397 (7th Cir. 2012). Summary
judgment is appropriate if there is no genuine dispute
of material fact, and the movant is entitled to judgment
as a matter of law. Id. Importantly, before this court
Ferraro argues only that the district court erred in con-
cluding that HP was entitled to summary judgment under
the consumer-expectations test. She does not contest the
district court’s holding that no reasonable jury could find
for her under the risk-utility test, nor does she assert
that the district court erred in granting summary judg-
ment on her failure-to-warn and implied warranty of
merchantability claims.
  It is unfortunate for Ferraro that we must leave the risk-
utility analysis untouched. This is so because it
would have taken center stage, given our inclination to
agree with Ferraro’s challenge to the district court’s
consumer-expectations analysis. The latter test asks
whether a product is “unreasonably dangerous” in the
sense that it was “unsafe when put to a use that is reason-
ably foreseeable considering its nature and function.”
Mikolajczyk, 901 N.E.2d at 352; IPI Civil (2006) No. 400.06.
The district court believed that Ferraro would be unable
to prevail under this standard, since “fall[ing] asleep
while using the computer . . . is not the intended use of a
power adapter.” But we find this focus to be unduly
narrow. It overlooks the fact that laptops are designed
10                                              No. 12-2616

precisely to be used in comfortable places, including
sofas, beds, La-Z-Boys, or other places where people may
nod off. By taking such a restricted view of the precise
manner in which Ferraro’s harm materialized, the court
sidestepped the undisputed fact that, at the time of her
injury, Ferraro was using the power adapter to do just
what it was designed to do: charge her laptop. Ferraro
is not arguing that the power adapter overheated when
she tried to use it to heat her blanket, or that it made for
a poor drink coaster or paperweight; rather, she asserts
that it was unreasonably dangerous when used for its
intended purpose. Cf. Calles, 864 N.E.2d at 256 (“We
now consider whether the Aim N Flame meets the
consumer-expectation test. The purpose of a lighter,
such as the Aim N Flame, is to produce a flame.”).
  HP may be correct that Ferraro was not using the prod-
uct in the precise manner intended by the manufacturer,
insofar as the power adapter was designed to rest on a
flat surface with ample ventilation, but this is beside the
point. The appropriate inquiry for the consumer-expec-
tations test is whether the product performed as safely
as an ordinary consumer would expect when used in
“an intended or reasonably foreseeable manner.” Lamkin,
563 N.E.2d at 457 (emphasis added). The great virtue of
a laptop is that it can be used on one’s lap, while sitting
on a sofa, or perhaps while in bed. Indeed, we note that
the Facebook page for “Using the laptop in bed” (Mission:
“Public awareness of the usage of laptops in bed”) has
nearly one million “Likes. ”See https://www.facebook.com/
pages/Using-the-laptop-in-bed/95445955714?fref=ts (last
visited June 28, 2013). Our analysis would be no
No. 12-2616                                                11

different if the power adapter had started a fire in the
sofa while Ferraro was in the next room; in either case, the
consumer’s use of the product would be the same. A
jury could conclude that Ferraro was using the power
adapter in a “reasonably foreseeable” manner when
the relevant harm occurred.
   This is not to say that the district court’s concerns
about the manner in which Ferraro was injured are ir-
relevant under the consumer-expectations test: even
if she were to succeed in showing “unreasonable dan-
gerousness” under this approach, to prevail at trial
Ferraro still would need to prove that the defective
design proximately caused her injuries. See Gilbertson v.
Rolscreen Co., 501 N.E.2d 954, 957 (Ill. Ct. App. 1986) (“Even
if we were to accept the plaintiff’s argument that [the]
‘product’ was unreasonably dangerous, we would still
be compelled to find for the defendants here, for the
defendants have not been shown to be the legal cause
of plaintiff’s injury.”); Kleen v. Homak Mfg. Co., Inc., 749
N.E.2d 26, 31 (Ill. Ct. App. 2001) (“A plaintiff must prove
that the alleged defect in the product was an actual [proxi-
mate] cause of the injuries rather than a mere condition.”).
  This is a separate inquiry under Illinois law, focused
on whether the power adapter’s defective design was a
cause that “in natural or probable sequence, produced
the injury complained of.” IPI Civil (2006) No. 400.04
(Strict Liability—Proximate Cause—Definition). A jury
might conclude that it was “natural or probable” for a
dangerously hot power adapter to start a fire, but not
“natural or probable” for it to burn a consumer who, for
12                                             No. 12-2616

whatever reason, failed to react when her skin came
into direct contact with the hot surface. Liability might
depend on how the jury resolved competing expert
testimony regarding the incorporation of pain into one’s
dreams, or the jury’s opinion of how unusual it is
for consumers to use laptops “under [ab]normal physio-
logical conditions” (e.g., under the influence of alcohol,
prescription drugs, or sleeping aids). Proximate cause,
however, “is generally a question of fact” to be resolved
by the jury, not the court. Young v. Bryco Arms, 821 N.E.2d
1078, 1086 (Ill. 2004).
   Whatever the merits of her arguments under the
consumer-expectations test, however, Ferraro’s failure to
challenge the district court’s risk-utility determination
is fatal to her appeal. As we noted at the outset, there
are two methods of proving unreasonable dangerousness
under Illinois law, and a plaintiff may prevail under
either the consumer-expectations test or the risk-utility
test. As the Supreme Court of Illinois recently explained
in Mikolajczyk, however, the existence of two tests raises
the possibility that a “product could be found unrea-
sonably dangerous under the consumer-expectation
test, but risk-utility analysis could reveal that an alter-
native is not available, or that available alternatives are
not feasible, or that the benefits of the design outweigh
its inherent risks.” 901 N.E.2d at 349. Where the two tests
yield conflicting results, the Mikolajczyk court held, the
risk-utility test “trumps,” and the product is deemed not
unreasonably dangerous (notwithstanding consumers’
expectations that the product would be safer). Id. at 352.
Unless “both parties’ theories of the case are framed
No. 12-2616                                                13

entirely in terms of consumer expectations” (and Ferraro
conceded at oral argument that this is not the case here),
this “broader [risk-utility] test . . . is to be applied by
the finder of fact.” Id.; IPI Civil (2006) No. 400.06A,
Notes on Use.
  The district court considered whether Ferraro could
prevail under the risk-utility test and determined that
“none of the risk-utility factors weigh in Ferraro’s fa-
vor.” As part of this analysis, the court acknowledged
that two of Ferraro’s experts offered opinions re-
garding other potential designs for the power adapter,
but it emphasized that neither expert “present[ed] any
evidence discussing the feasibility of any of these alter-
natives.” The court also weighed “the magnitude
and probability of the foreseeable risks of harm,” noted
HP’s evidence of compliance with relevant regulatory
standards, and highlighted the absence of any “history
of severe burns associated with the HP power adapter.”
This was enough for the district court to conclude that
no reasonable jury could find for Ferraro under the risk-
utility test.
  As we said, we express no opinion on this part of the
district court’s analysis. Ferraro’s “failure to advance
on appeal any arguments with respect to this alternate
ground means that any challenge to that ground is
waived.” Senese v. Chi. Area Int’l Bhd. of Teamsters Pension
Fund, 237 F.3d 819, 823 (7th Cir. 2001); cf. Hess v. Reg-Ellen
Mach. Tool Corp., 423 F.3d 653, 664-65 (7th Cir. 2005).
Absent some argument to the contrary, we must accept
that no reasonable jury could find for Ferraro under the
14                                              No. 12-2616

risk-utility test, which is the approach upon which HP
would be entitled to insist at trial. HP thus remains
entitled to summary judgment.
  Because there is a sufficient and unchallenged ground
of the district court’s decision, we A FFIRM the judgment
of the district court in favor of HP.




   M ANION, Circuit Judge, concurring. The district court
ruled that the power adapter was not “unreasonably
dangerous” under the risk-utility test, and as the court
correctly concludes, the risk-utility test “trumps” the
consumer-expectation test when the two tests yield
conflicting results. See Mikolajczyk v. Ford Motor Co., 901
N.E.2d 329, 349-53 (Ill. 2008). Because Ferraro did not
appeal the district court’s ruling on the risk-utility test,
I agree with the court that we should affirm.
  While I agree with the court’s decision to affirm, I am not
inclined to join with the court’s discussion of the
consumer-expectation test. Rather, I think that the
district court correctly analyzed this issue. Under the
consumer-expectation test, we examine whether the
product “failed to perform as safely as an ordinary con-
sumer would expect when used in an intended or rea-
sonably foreseeable manner.” Lamkin v. Towner, 563 N.E.2d
No. 12-2616                                           15

449, 457 (Ill. 1990). Ordinary consumers know that
power adapters can become hot (including when
laptops are used in beds and other comfortable places).
Indeed, this common knowledge was demonstrated by
Ferraro’s daughter, who testified that her mother knew
that power adapters can become hot. If HP’s power
adapter could become so hot that it would quickly cause
a user to react and withdraw, a jury would likely be
entitled to decide whether the power adapter is “unrea-
sonably dangerous.” But the power adapter in this case
merely “performs as safely as an ordinary consumer
would expect.” Therefore, given the unusual circum-
stances that caused the injury in this case, a reasonable
jury could not find that the power adapter is “unreason-
ably dangerous.”




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