Hard to say if it's a problem or not based on your description. Are they in pots or in ground? How much/often are you watering. Do the look better in the morning? How old are they.

It can be hard to nail down plant problems. Personally, I have peppers in 25 five gallon pots and a bunch in the ground. Three of the potted ones seemed to have developed an aversion to daylight 8-) As the day progresses they droop leafs and plants to the point of looking dead. Overnight, they bounce back and thrive. First thing in the morning they look like the healthiest plants of the bunch, no flower drop etc. and the cycle repeats. Still trying to figure it out.

Bill

Many plants droop in the warm afternoon.
If they're in pots, move them into a shady location and I can almost guarantee that
they'll perk back up in less than 30 minutes. If not, you might have a problem.....

If the soil is too heavy - too water-retentive - the roots might not be able to take up moisture.
The addition of a wick - synthetic shoe-string, for example, poked into the media
through a drain-hole - should allow excess moisture to depart and oxygen to return.

Really hard to guess based on the minimal information provided.

Josh

I'm having the same problem with my Bhuts and Habaneros. After a short time (about an hour) in the direct sun, the leaves get all droopy and I have to bring them inside.

I still keep them in the sun, only it's just inside the patio door. They always perk right back up. Can't figure it out.

Hate to think that I'm going to have to do this every day for the rest of summer.

You've already figured it out. Totally natural response to heat.
More moisture is evapotranspirating from the leaves than the plant can draw from the roots.
Slow that process with a bit of shade/mosaic sunlight, and the problem will be solved.
Leave them outside where the air can still circulate and toughen the leaves and branches.

Sometimes, shading the container itself is enough to cool the roots.

Josh

Pepper plants are little weenies. All of mine droop a bit if the sun is too intense. They are just conserving water.

I have some under a light shade cloth, but the ones out in full sun actually seem to do better. It's just that they snivel when it gets too hot.

If they are drooping, don't automatically water. Check soil moisture before you water, because they will droop when they don't need to be watered.

It's a bit of a joke around here. The fruit will blow your lips off, but the plants are little primadonas.