The National Weather Service in North Little Rock on Monday issued a heat advisory that covers most of the state.
The advisory covers large parts of central, east and south Arkansas, the agency said.
Temperatures are forecast to reach a high of 101 degrees, and afternoon and early evening heat indexes are expected to rise to near 105 degrees and could exceed 110 degrees in some areas.
The advisory will remain in effect until 7 p.m. Monday, according to the agency.
The combination of high temperatures and high humidity increases the risk for heat-related illnesses. The agency advises people dealing with hot conditions to stay in air-conditioned areas and out of the sun as much as possible and to keep hydrated.