The heat advisory and heat plan applied to all of Maryland on Friday, June 29, and will be in effect on Saturday, June 30 and Sunday, July 1, for all regions of the state, except western Maryland, according to officials.
During the week of June 19-25, 325 people in Maryland were stricken with heat-related illness, according to the Maryland Department of Health and Mental Hygiene.
Data for heat-related illness this week won't be available until next Tuesday, according to health department officials.
So far in 2012, there have been no heat-related deaths in Maryland, according to state officials.
In 2011, there were 34 confirmed heat-related deaths between May and August. There were a total of 32 deaths in 2010, six heat related deaths in 2009, 17 in 2008 and 21 in 2007, according to state records.
According to health officials:
Heat-related illnesses include heat stroke -- a serious condition marked by a body temperature more than 105 degrees -- and a milder form known as heat exhaustion.
Heat stroke can develop rapidly, and include symptoms such as dry red skin, convulsions, disorientation, delirium and coma. Treatment of heat stroke involves rapidly lowering the victim's body temperature with a cool bath or wet towels.
The victim of heat stroke should remain in a cool area while emergency care is obtained by dialing 911.
Heat exhaustion can develop more slowly, and include signs such as weakness, muscle cramps, nausea, and headache. Heat exhaustion is treated with plenty of liquids and rest in a cool, shaded area.
For more information, visit the state's extreme heat web site.