Are you feeling summer’s sizzle? All that sun and heat can affect your body in ways you’ll never suspect.

By Victoria Veilleux
Updated July 07, 2014
Jamie Chung

You’ll sweat more but not necessarily stink more. Skin bacteria eat stress-induced sweat, emitting a smelly by-product. They’re less drawn to heat-induced sweat (secreted by different glands).

Skin becomes less sensitive. The moisture in humid air is soothing. So try using wrinkle or acne treatments daily instead of triweekly, says dermatologist Whitney Bowe.

Bad cholesterol drops by about 3 percent, says a new Johns Hopkins study. That’s probably in part due to diet. Digestion creates heat, so the brain signals for a smaller appetite in warm months, says Linda Rinaman, Ph.D., a professor of neuroscience at the University of Pittsburgh.

Kidney-stone cases rise 13 percent for every 2 degrees the ambient temperature goes above 85 degrees Fahrenheit, due to dehydration, says one study. Combat them with lemonade, says Timothy Averch, a professor of urology at the University of Pittsburgh. Its citrate keeps urine salts dissolved, so they won’t form stones.

You can still catch a bad cold. The heat-loving enterovirus can trigger similar symptoms to those of the winter rhinovirus but may linger longer, says Bruce Hirsch, M.D., a Long Island–based infectious-disease specialist.

Your vision might suffer. Some data suggests those in warm climates need reading glasses sooner than those in cooler ones. It’s unclear why. There’s no sure way to delay bifocals, says Paul Kaufman, the chair of ophthalmology and visual sciences at the University of Wisconsin–Madison, but UV-protectant shades are a good idea for optimizing eye health.