Temperature vs. relative humidity scale[/caption]

As summer sets in, temperatures are on the rise and more people are at risk to heat-related illness.

Heat waves are the leading cause of extreme weather-related deaths in the U.S., the CDC says. Texas had 74 counts of heat-related deaths in the summer months of 2014, according to the CDC. In 2008, 2009 and 2010, the number of deaths exceeded 100, and in 2011, one of the hottest years on record in Texas, more than 200 people died from heat-related causes.

In urban areas, where buildings block breezes and absorb and radiate heat rather than reflect it, temperatures can be 1-5 degrees warmer during the day and up to 22 degrees hotter at night, according to a booklet published by the CDC and EPA. Temperatures do not have to be extremely high for heat-illnesses to occur. Temperatures in the low to mid-90s can be extremely dangerous when relative humidity is high.

Use these tips from the CDC to avoid heat-related problems like sunburns and heat rash as well as more serious illnesses like heat exhaustion and heat stroke.

1. Don’t wait until you’re thirsty to drink water


Staying hydrated keeps the body healthy and helps regulate temperature. Drinking cold water throughout the day will help keep body temperatures at healthy levels.

2. Wear loose-fitting, lightweight and light-colored clothing


Dark and heavy clothing absorbs more heat and traps it against the skin. It also soaks up sweat. Wearing loose-fitting clothing allows heat to escape and lets sweat evaporate from the skin, which is the body's natural mechanism for cooling down.

3. Plan carefully for outdoor activity


Whether it’s for work or play, the safest times to be outdoors in the summer are in the morning and evening when it’s cooler. Avoid direct sunlight during the hottest parts of the day, wear a hat and rest in the shade whenever possible.

4. Use sunscreen


Apply sunscreen SPF 30 or higher at least 30 minutes before engaging in outdoor activities. It helps prevent sunburns, which limit the body’s ability to cool down and can cause dehydration. Reapply often.

5. Find ways to cool down


According the the CDC, an electric fan is not capable of preventing heat-related illness in temperatures reaching the high 90s. If anyone does not have air conditioning in their house, visit the public library, grocery store or shopping mall for a few hours to cool off. A cold shower or bath is also effective.