Scrubs. 😀
But for non-scrub wearing types (or those in hospitals that don't allow them), civilian clothes are best. As noted in the post above, most hospitals are cold, so you don't really need to worry about the hot days...matter of fact, in the old days when I was an intern and junior resident I never even knew it was hot outside since I was inside 120 or so hrs per week. But you will be coming in fewer hours and only really have to worry about temperature extremes during your commute.
I would shy away from open toe shoes unless you are absolutely not going to come into any contact with bodily fluids (even Psych ventures into patients rooms occasionally, so I am loathe to think of a specialty which does not).
I would also shy away from skirts for some of the same reasons - kneeling down, sitting down, etc. you don't want to worry about your legs showing too much or getting bodily fluids on them. But again, this depends on what kind of patient contact you will have. I would not wear an above knee skirt on any occasions because the minute you sit down it becomes a mid-thigh skirt which is WAY too short for professional duties. I do not feel much need to wear pantyhose.
The biggest mistake medical students and new residents make is being too casual. Jeans, sweatpants, crop tops, spaghetti straps and the like are NOT appropriate work wear in the medical profession. If you want to wear a sleeveless top, that is fine since you will be covered with a lab coat or cardigan but it should have straps wide enough to wear a bra underneath.
No dangly jewelry which babies can grab (if on a Peds specialty) or which can get tangled up in your stethoscope.
Otherwise, just use your common sense, avoiding the things noted above, and you should be fine.
