It's almost the end of summer...well maybe for most. Here in Charleston, SC, we've had multiple 80 degree Christmas Days. Here's the problem when it comes to heat and your tennis racquet/strings. Both your racquet and strings would love to live on the beach in Southern California, where it's consistently in the 70s (wouldn't we all). Tennis strings (specifically polyester) HATE temperatures above 95 degrees! One specific study, conducted by TWU (Tennis Warehouse University), concluded that leaving a freshly strung racquet in a car on a hot day (heated to 104 degrees F, 40 degrees C) sustained between 30-76% tension loss. Let's put some more numbers to this: Leaving your racquet in your car in direct sunlight after being freshly strung at 55 lbs., will go from 55 to 39 lbs. if you happen to get lucky at the 30% loss.
THAT IS RIDICULOUS!
Unless of course you're Jack Sock playing playing with a fresh bed of poly at 40 lbs...
And then say you don't get so lucky...stiff polys lost the most tension when heated. Those at 55 lbs. are now around 20 lbs. Good luck with your butterfly net!
Lastly, it's not only the strings in trouble. It's much harder to assess but the molecular structure of racquets do change when heated. This could specifically impact racquet flex and stability at impact.
So what can we do? For many it may take some serious will power to remember to take their racquets out of the car, but developing a new routine is WELL WORTH IT and could save you over $100 a year in string jobs.
Try your best to keep your racquets in a room temperature environment. This may mean taking them with you into school, work, etc. DO IT! Don't leave them in the car, even if you think it's not that hot outside.