In the summer as I am going to and from work, I like to play a little game. I look at all the women rushing by on the sidewalk and I try to guess where they work, based on what they are wearing. Sometimes it’s obvious. Anyone in a suit and pantyhose with closed toe pumps on a sweltering July day must surely work in a very conservative environment such as a bank or law office. Otherwise, no one would choose to dress that way in such heat. But, in recent years, it has become much harder to guess the rest.

I don’t know when it became common for young women to wear strapless cotton jersey maxi dresses and flip-flops to the office, but I see plenty of them these days. Women of all ages make bra mistakes, such as wearing a regular bra with an open-back dress or racer back top. I recently saw a middle-aged woman in my building wearing a paisley chiffon poncho with Lycra bike shorts! And it wasn’t even a “casual Friday”!

Here’s a simple rule of thumb about getting dressed on hot days: if you could wear it to the beach or the gym, you probably shouldn’t wear it to the office.

No matter what your age, it’s important to keep in mind that the bar for dressing professionally doesn’t drop just because of the temperature rises. So here are some simple tips for staying stylish and comfortable.

Dresses: Loose, tunic-like dresses or shifts are generally more comfortable than fitted styles, but the proportion is key. These look best if they hit just at the top of the knee or a few inches higher, depending on your age and your comfort in showing your legs. If you are self-conscious about wearing a sleeveless dress, toss a light cotton jacket or cardigan over your shoulders. A fit-and-flare shirt dress in cotton or silk is another great, easy-to-wear choice.