炎热的夜晚

影片着力塑造了黑人警官维吉的英雄形象。维吉正直,善良,坚持真理,支持公道，又具有高超的凶杀案破案能力。当他身处种族歧视严重的密西西比州时，对那无知警察的无理拘捕只能忍让；面对警官比尔的傲慢轻视，表示宽容，必要时亮出身份，不卑不亢。他对比尔明确指出：他抓错了人，尽到一个警官应尽的职责。在死者妻子的要求与比尔的激励下，答应参与破案；面对四个歹徒欲将他置于死地，毫无惧色，一身豪气，奋勇搏斗。他对有钱白人先是给予礼仪，对他恶意影射的语言置之不理，挨了一下后立即还以更响亮的一记耳光。即便是对本无好感的白人，也决不冤枉。他的这些行为，充分表现出他的优秀品质；而这些品质,无论对哪个种族,对哪个阶层的人来说，都是难能可贵的。 影片描述的故事，是发生在1962年，即马丁.路德.金率二十万人向华盛顿"自由进军"的前一年，地点在密西西比州。影片如实地反映了当时当地种族歧视情况严重的社会现实：那些无知愚昧的白人对黑人极为仇视，有的敢当面骂维吉“黑鬼”，有的轻易就做歹徒去追杀维吉；那白人有钱人居然敢给黑人警官一记耳光，还说如在几十年前会一枪毙了他。但也有那死者的妻子，坚持要维吉来办她丈夫的案子，可说是个明白人。而警长比尔更是从开始对维吉傲慢无礼到肯定他的才干；从激励他留下参与办案到又诚心希望他离去以免遭不测；带他去到一个黑人汽修工家住宿；及时帮维吉解除十分危急的境况，还给了一白人歹徒狠狠一拳；对那有钱白人对维吉的无礼很表反感，而对维吉还他的一记耳光，在心里深表称许；最后，亲送维吉上火车，微笑着真诚地要他“保重”。可见，比尔的所作所为，代表了有良知的美国人，是当时美国时代精神的一个方面的反映。从而，到1964年，约翰逊总统签署了“人权法案”。 影片中还有两处细节描写了黑人：一是黑人汽修工对维吉来他家表示高兴；再是有钱白人的仆人对他的主人瞪了眼睛，微微摇头。这些，影片都有其用心。 时代前进了。类似影片中那种严重的种族歧视的事，现今虽不能说完全没有，毕竟不会重现，而种族偏见的情况随处可见。影片是有它的永久的警世意义。

Philip Colbert, a wealthy man from Chicago who was planning to build a factory in the rural town of Sparta, Mississippi, is found murdered. Police Chief Bill Gillespie (Rod Steiger) comes under pressure to quickly find Colbert's killer. African-American northerner Virgil Tibbs (Sidney Poitier), passing through, is picked up at the train station by a police officer (Rod Steiger) who finds Tibbs with a substantial amount of cash in his wallet. Officer Gillespie, heavily prejudiced against blacks, jumps to the conclusion that he has his culprit, but is embarrassed to learn that Tibbs is a respected Philadelphia homicide detective who had been visiting his mother. After the bigoted treatment he received, Tibbs wants nothing more than to leave Sparta as quickly as possible, but his captain recommends he stay and help the investigation. The victim's widow, already frustrated by the ineptitude of the local police, is impressed by Tibbs' expert ability when he clears another wrongly-accused suspect Gillespie has arrested on flimsy evidence. She threatens to stop construction on the much-needed factory unless Tibbs leads the investigation. Unwilling to accept help but under orders from the town's mayor, Gillespie talks Tibbs into lending his services. Despite the rocky start to their relationship, the two police come to respect each other as they are compelled to work together to solve the crime. Tibbs initially suspects wealthy plantation owner Eric Endicott, who opposed the new factory. When he attempts to interrogate Endicott about Colbert, Endicott slaps him in the face. Tibbs slaps him back, which leads to Endicott sending a gang of redneck hooligans after Tibbs. Gillespie rescues Tibbs from the fight and orders him to leave town for his own safety. Tibbs refuses to leave until he has solved the case. Tibbs asks Sam Wood, the officer who discovered the body, to retrace his steps the night of the murder. He and Gillespie accompany Sam on his patrol route, stopping at a diner where the counterman, Ralph Henshaw, refuses to serve Tibbs because he is black. When Tibbs notices that Sam has deliberately changed his route, Gillespie begins to suspect Sam of the crime. When he discovers that Sam made a sizable deposit into his bank account the day after the murder (which Sam claims was gambling winnings) and Lloyd Purdy, a local, files charges against Sam for getting Purdy's 16-year-old sister, Delores, pregnant, Gillespie arrests Sam for the murder over Tibbs' protests. Purdy is insulted that Tibbs, a black man, was present for his sister's interrogation about her sexual encounter with Sam, and he gathers a lynch mob to get his revenge on Tibbs. Tibbs is able to clear Sam by finding the original murder scene and pointing out that Sam would not have been able to drive two cars at the same time to dump the body and the victim's car while continuing on his patrol. Acting on a hunch, Tibbs tracks down the local back-room abortionist, who reveals that someone paid for Delores Purdy to have an abortion. When Delores arrives, Tibbs pursues her outside, where he is confronted by the murderer: the diner counterman Ralph Henshaw. Purdy's mob tracks down Tibbs at this moment, and he is being held at gunpoint when he proves to Purdy that it was Ralph, not Sam, who got Delores pregnant. Purdy attacks Ralph, who kills Purdy in self-defense. Ralph is arrested and confesses to the murder of Colbert. He had attempted to rob Colbert to gain money to pay for Delores' abortion but accidentally killed him. His job done, Tibbs finally boards the Gulf, Mobile, & Ohio train out of town, seen off by a more respectful Gillespie.

本片黑人警察维吉尔和白人警长都有人物弧光设计。

黑人警察因为被冤枉、被侮辱所以认定种植园园主是凶手，但被警长“原来你和我们剩下的人都一样”一语点破，知道自己犯了主观认定先行的错误，后来根据新的证据查出真相。

白人警长一开始只将维吉尔作为黑人看待时也歧视侮辱维吉尔，但随着当得知他的警察身份，并了解到他很有刑侦能力，维吉尔指出自己对小偷的判断失误，给出尸检信息的过程中，逐渐将他作为一个警察同行来看待，所以当维吉尔得罪种植园园主时，警长并没有惩治维吉尔，而是为他的安全考虑让他离开，并前去救他。最后，当维吉尔找到真凶送他离开时，一句再次强调的“保重”对他流露出赞赏和关心之情。

本片将受害人的身份设置得比较重要，将这件案子显得比较重要。并设置了维吉尔、小偷、种植园园主、巡警山姆等四次误导，最终才找到真凶。过程波澜起伏，并通过破案的过程展现出小镇的种族歧视、警察办公状态等社会状况。

主线是破案的过程，副线是黑人警察与白人警长的关系变化。

本片的音乐很有特色，例如在开头警察巡视时慵懒的爵士乐反映了小镇的宁静和警察的慵懒。在维吉尔被追杀时采用了非常紧迫感和节奏感的音乐，对于带动观众紧张感很有帮助。本片节奏张弛有度，将案件调查与人物情感交流与变化恰到好处地交织在一起。

另外，本片在表现追逃场面时，使用了大量斯坦尼康主观镜头与跟随镜头，剪辑节奏和景别的变化也表现出了形势的紧迫程度。如，警察们在抓捕小偷时，先使用了快速剪辑的主观镜头和近景跟随镜头，当警长开着车慢悠悠等待小偷体力耗尽时，镜头长度变长，并且景别变成了远景。

但是最终的真相过于幼稚简单。