Mexico - Several Mexican states, including Tamaulipas, Veracruz, Coahuila and Guerrero, have issued heat advisories to residents as temperatures rise above 37 C (98.5 F), the Mexican National Water Commission, or Conagua, reports.

"For 2014, based on the monthly forecasts, it is expected that the midsummer heat will be moderate; however, it could be intense in some regions," the Conagua said in a recent statement.

Low precipitation is likely in August, mainly in eastern, western, southern and southeastern Mexico, as well as above average temperatures, the Conagua said.

The midsummer heat is a climatic event that affects different regions of Mexico year after year, with high temperatures and scarce rainfall.

The climatic event usually starts in July and can last until early September in some states.

"The midsummer heat is part of the changing weather in Mexico and its intensity and seasonality is different in each region since it is related to the annual rain cycle in the Mexican Republic," the Conagua said.

The climatic event affects agriculture because growing areas depend on rain and low precipitation can threaten corn and other crops, causing prices to rise.

Residents should monitor the daily bulletins and advisories issued by the weather service, the Conagua said.

High temperatures can cause gastrointestinal illnesses, dehydration and heat stroke, the federal agency said, adding that people in affected areas should follow Health Secretariat guidelines for dealing with intense heat.