A summer heatwave and lengthy gaps between races make for dangerously idle hands and mischievous gossip in the F1 paddock, with this year's prime subject for speculation being Lewis Hamilton and his state of mind out on the track following his latest reported break up from long-time girlfriend Nicole Scherzinger, which Hamilton himself conceded was proving hard for him to put to one side even at race weekends.

"I wear my heart on my sleeve and that gets me in trouble a lot of the time and I generally find it very, very hard to fight my emotions," he explained recently, talking with Sky Sports F1's Martin Brundle in Germany. "You have different people who are able to hold in their emotions - I have a Finnish trainer, for example, who doesn't show any emotion and they are always able to control it.

"I'm going through ... I'm trying my hardest to be positive but I'm going through a really, really tough time at the moment with the loss of someone really, really special in my life," he admitted, confirming that he was referring to Scherzinger. "My world's turned upside down."

Coming into the 2013 season, Hamilton had been widely expected to be installed as Mercedes' undisputed number one driver after he joined the team at the start of the year. It was a suspicion that was borne out when team orders were used to prevent Nico Rosberg overtaking him in Malaysia, which secured the Briton a podium position. But although he's gone on to pick up two further podium finishes in 2013, Hamilton has been unable to improve on third place so far this season and instead it's Rosberg who seems to have been boosted by the arrival of a new team mate, leading him to pull off two Grand Prix wins at Monaco and Silverstone.

Hamilton has still been very strong in qualifying and has started on the front row for six of the nine races so far this year, including back-to-back poles in the last two races. However, tyre wear issues with the 2013 Pirellis have seen him drop back in every race bar Sepang, leaving the 28-year-old increasingly frustrated and outspoken as the season has gone on.

"The car is a disaster on heavy fuel loads," he said after the German Grand Prix, uncharacteristically outspoken and negative about the state of things at Brackley. "It's always a shock when a race goes bad. You never expect it to go as bad as it does. You find you are digging yourself out of a hole right towards the end of a race when all of a sudden the car starts working. It's very frustrating.

"I'm not really thinking about the championship now," he added. "There's really no point." He was also put out not to be able to take part in the test of new-specification Pirelli compound tyres last week at Silverstone, saying: "People don't appreciate how big a negative it is for us not to do the test."

Such downbeat talk from Hamilton ahead of the midpoint of the current world championship season has led some in the F1 paddock to wonder if his mental approach to the day job in light of personal stresses and strains away from the car is once again proving to be his Achilles Heel - and what that might mean for Hamilton not only in 2013 but looking further ahead in his career. Will such worries always risk thwarting a second world championship title bid?

Hamilton and Scherzinger were reported to have broken up at the start of July, and his posts on Twitter in the last few days suggest that he's taken the end of their long-term relationship very much to heart. "If you've found that special someone, don't EVER let them go no matter what!! Nothing in this world is more important," he posted on the social media network.

"Nicole and Lewis split due to hectic work schedules and his refusal to commit," a source told Star magazine. "But he's having a hard time away from Nicole. He's starting to see what he's lost."

The two originally got together in 2007, but an earlier break-up in 2010 and 2011 was partly blamed for a poor string of performances by Hamilton in that year's championship battle. Hamilton later admitted that issues in his personal life had been getting to him and been impacting his driving, and that he envied his then-McLaren team mate Jenson Button's more stable personal situation which saw him surrounded by friends and family in the F1 paddock for every race, including his own long-time girlfriend Jessica Michibata.

"Jenson's done a great job to get things in the right place. He's got his dad there at every single race, he's got his management there, he's got his friends, he's got his girlfriend there all the time," Hamilton said at the end of the 2011 season. "He's in a really, really happy [place]. He's got a great bubble around him which he's very happy with and with that he's able to just go out and perform without any worries on his mind ... I did have [that] at one point and lost that bubble and I don't have that around me at the moment."

Reuniting with Scherzinger in 2012 put Hamilton back into a happier state of mind and that was reflected by his on-track performances within the limitations of that year's McLaren car, but Scherzinger's own work commitments which include being a judge on TV's The X Factor have meant she is an unavoidably infrequent presence in the F1 paddock at race weekends.

"It's so hard to keep up a relationship when they're barely in the same country as each other," admitted a source close to the couple. "Both have supported each other in their careers and will continue to do so, but the nature of their work ultimately cost their relationship."

But will the latest break-up now free Hamilton up to focus on his on-track activities, or will it instead hang heavy over the driver for the remainder of the 2013 season? For his part, Hamilton insisted that he was well aware that he has a job to do, regardless of his personal circumstances.

"I'm really trying to pull myself together and keep my head up but it's so hard to do," he said. "I have a job to motivate my team and if I come in with my head down and negative energy then that goes around to all my mechanics who work day and night, and I don't ever want that.

"When I get in the car I generally switch off and I feel at home and I feel in control and I'm in my own world," he said. "It's just me in the car on the track and nothing else. So that's when I feel my best and I feel most comfortable in my life."

That means it's ironically the breaks and holidays between races when he's away from the race track that are the most difficult and distracting times for him at the moment - not a good sign given the three-week hiatus between Germany and Hungary, which will be followed by a month off for the traditional F1 August summer shutdown until Spa.

Sure enough, he revealed that he had been spending the three-week gap between most recent races working on a song for Scherzinger in a recording studio in London: "My hideaway - pouring my heart into this track!!" he posted on Twitter.

Other reports have similarly suggested his long-term attention might currently lie away from the track: "Lewis finishes up his F1 commitments in November and is planning to fly straight to the UK to be here for Nicole while she films the live X Factor shows," said the source.

As for Scherzinger, comments from her carried in the tabloid press suggest that she's also unhappy about the break-up - but that she's made the first decision to put her work life first. "You just make those sacrifices and they made me feel so at home last year. It is hard but you always make those sacrifices and it's worth it.

"It gets lonely but I'm working all the time," she told The Sun newspaper. "I don't have anyone here, I don't have my family, I don't even have any friends here. My publicist is my closest friend."

The question now is whether or not Hamilton can find the same single-mindedness to put him back on track to winning more races and championships with his new team. Hamilton certainly has his supporters who insist he can do just that, which include broadcaster and former F1 driver Martin Brundle.

"He needs to find a way pretty soon to be able to package that up and be able to manage his private life and make sure he's maximising his racing life," Brundle told Sky Sports News this week. "Lewis is still in there, [so] I wouldn't write him off.

"He's made a great decision it seems in going to Mercedes-Benz," he added. "He's got some points on the board so he's not out of sight already. He's got the pole positions [even if] the victories haven't come his way; two have gone to Rosberg of course, his team-mate, who's driving beautifully.

"There's a long way to go in this championship. Halfway through the Hungarian Grand Prix is halfway through the championship season, so many points to come."