The survey of 6,000 adults saw 78 percent admitting they were moodier in July.
Nearly 88 percent said they lost sleep every night, with two hours being the average.
About 70 percent of parents reported bring woken up at least three times a night by kids struggling in the heat.
According to the survey, by Travelodge, frustration would push one in two (49 percent) drivers travelling in the heat to shout at another motorist.
One-fourth said they would use foul language, 40 percent would employ rude gestures and one-fifth would tailgate another driver.
About 27 percent commuters said they were likely to shout at a partner or child while travelling in hot conditions.
The weather also raised tempers at workplace, with 45 percent of workers confessing they took their irritation out on colleagues.
The scorching sun also raised health problems, with 40 percent suffering sunburn, one in five being laid low by hay fever or worsening asthma and 15 percent suffering heat-related migraines.
A little more than 80 percent also admitted to getting fed up in July because they were too embarrassed of their bodies to strip off and soak up the sun.
"We wait all year for the hot weather, but when it arrives, most of us aren't prepared," The Scotsman quoted Leigh McCarron, Travelodge sleep director, as saying.
He added: "The lack of sleep makes us irritable, that combined with soaring temperatures in the day make many of us quite tense. We like the heat - but it takes us time to get used to it." (ANI)