Some tips to beat the excessive heat:

• Stay indoors, preferably in air-conditioned areas. The D.C. Homeland Security and Emergency Management Agency has listed designated cooling centers throughout the city on its Web site. Cooling centers also are open in Rockville and Laurel and in Prince George’s County.

• Drink plenty of water, even when not thirsty. Those performing strenuous activity in the heat should drink two to four glasses of water every hour.

• Wearing lightweight, loose-fitting clothing will keep the body from overheating.

• Apply sunscreen of SPF 30 or higher before venturing outdoors. Wearing sunglasses and wide-brimmed hats may also provide protection from the sun’s rays.

• It is best to limit outdoor activity to morning and evening hours when the temperature is lower.

Some tips on recognizing potentially dangerous heat-related illnesses:

• Symptoms of heatstroke include throbbing headaches, dry red skin, disorientation, convulsions, delirium and chills. Heatstroke can strike in minutes and can cause death or a permanent disability. Someone with heatstroke needs medical attention as soon as possible.

• Heat exhaustion is a milder form of heatstroke with symptoms such as extreme weakness, nausea, headaches, heavy sweating and dizziness. The best way to treat the illness is with plenty of cool liquids and resting in shady or cool areas.

• Heat cramps are short, severe cramps in the muscles of the leg, arm or abdomen that can happen during or after heavy exercise in extreme heat. Heat cramps may be a symptom of heat exhaustion. Drinking plenty of water and getting rest are the best ways to treat heat cramps.

— Sarah Khan

Sources: D.C. Department of Health, Maryland Department of Health and Mental Hygiene