Men often joke that cold weather is to blame for a less-than-impressive bulge.
But scorching summer heat might not be such a blessing either.
Experts warn that ‘summer long balls’—the effect of penises and testicles appearing larger and hanging lower in hot weather—could actually spell trouble for fertility.
The effect, seen during last week’s 33.6C heatwave in Britain, is the body’s natural reaction to rising temperatures.
Dr Anika Ackermann, a board-certified urologist, told The Cut: ‘When it’s a cold environment, the testicles move towards the body, and the scrotum tenses up.
‘The opposite is true in a warm environment. The scrotum relaxes, and the testicles move away from the body.’
This shifting is designed to protect sperm. The scrotum—or scrotal sac—acts like a thermostat, moving the testes closer to or further from the body to stop them overheating or getting too cold.
While this temporary reaction can affect sperm production, experts stress it does not cause lasting damage to fertility.
Many men will experience temporary changes to the positioning and size of their penis and testicles as the weather changes. But for some this could wreak havoc with their fertility
However, according to leading urologist Dr Yaniv Larish, this phenomenon can also be caused by varicoceles, or enlarged veins in the scrotum.
‘When you have a varicocele, the blood is not moving around efficiently, so instead of circulating around the testicle and pulling the heat away, its pooling up and actually insulating the testicle at an elevated temperature,’ he explained.
According to John Hopkins Medicine, the condition is very common affecting around 15 percent of adult men.
Whilst for most varicocele will go unnoticed, Dr Larish said the condition can become ‘more pronounced’ in warmer weather.
This can cause a number of issues including reduced fertility, decreased testosterone and scrotal discomfort.
But experts say, in the majority of cases, whilst the warm weather may cause fertility to plummet, negatively affecting sperm quality, the effects is usually temporary.
However, in men with varicoceles, fertility could be an issue—though this is a vehemently contested theory.
One purported theory is that varicoceles can interfere with the body’s ability to make and store sperm but research on whether treating varicoceles cann improve fertility is mixed.
While the WHO estimates one in six adults globally will be affected by infertility in their life time there are regional variations
Either way, whilst there is no hard and fast cure for ‘summer long balls’, experts say there are a few things you can do to reduce discomfort.
Dr Ackerman recommends wearing tighter underwear for scrotal support and spending as much time in cooler environments as possible.
And if you don’t have an air-conditioned space to take refuge in, the urologist suggested investing in a pair of ‘Nutsicles’—essentially an ice pack for testicles primarily marketed at vasectomy patients—to keep cool all summer long.
The warning comes as research finds just a one degree increase in ambient temperature can lead to a drop in sperm production.
The study, published recently in the journal Biomedical and Environmental Sciences and reported last week by the Daily Mail, analysed semen samples from more than 6,600 donors worldwide over a six-year period.
On average, the mercury reached highs of between 6.7C (44F) and 18.2C (64.8F) across the nations sampled—with the highest being 42.1C (107.8F).
And the results showed those living in hotter climes had less sperm motility—the ability of the cells to move effectively, which is crucial for successful fertilisation.
Experts are calling for all men to be regularly monitoring their sperm from their late teens onwards in a bid to identify thousands of hidden cases of male infertility at an earlier stage.
Research suggests male infertility is a factor in about half of all cases where couples fail to conceive.
Yet many cases could be identified and potentially treated early if every man had a semen analysis when they turned 18 and again a couple of years later to monitor changes in sperm count and motility, argues Tet Yap, a consultant andrological surgeon at Guy’s and St Thomas’ NHS Foundation Trust and the private Princess Grace Hospital, both in London.
