When temperatures climb to 105º in Arizona, most people know the importance of drinking water, finding shade, and limiting time outside. But ABC15's Kaley O'Kelley learned about some common allergy medications that can change the way the body responds to extreme heat and sunlight.

Guidance from the Centers for Disease Control and Prevention shows that some antihistamines can reduce the body’s ability to sweat, including diphenhydramine, the active ingredient in Benadryl.

Sweating is one of the body’s main ways of cooling down. When sweating is reduced, the body may have a harder time releasing heat, especially during prolonged exposure to high temperatures.

Other allergy medications may affect the skin’s reaction to sunlight.

The Food and Drug Administration lists cetirizine, sold under the brand name Zyrtec, and loratadine, sold as Claritin, among medications that may cause photosensitivity, which can lead to a sunburn-like reaction, redness, irritation, or a rash.

The FDA says not everyone who takes these medications will experience a reaction, but there are several steps people can take to reduce the risk:

• Start by checking the medication label for warnings about sunlight, heat, or overheating
• When possible, seek shade and limit time outside during the strongest sunlight, especially between 10 a.m. and 2 p.m.
• If you do need to be outside, wear long-sleeved shirts, pants, sunglasses, and a broad-brimmed hat
• Use broad-spectrum sunscreen with an SPF of 30 or higher and reapply it as directed

Do not stop taking medication without first speaking with a doctor or pharmacist.

A pharmacist tells O'Kelley that the beginning of Arizona’s hottest months is a good time to review medications and ask whether they are still the safest fit during extreme heat.