People and plants need protection from extreme heat. Here's what to know.

BALTIMORE -- In Baltimore, city officials have declared a Code Red Alert for extreme heat through Wednesday.

Temperatures are well into the 90s, but with the humidity, it feels even hotter, into the triple digits.

Excessive Heat Warnings remain in place for the entire WJZ First Alert Weather viewing area through 8 pm. More heat warnings and advisories are likely Tuesday and Wednesday.

Cooling centers are now open across the city and are crucial to keeping people safe.

So far this year, there have been six heat-related deaths in Maryland.

Peter Bieneman, with Green Fields Nursery and Landscaping, told WJZ you should check your plants for signs of dehydration.

"Think just like you do for yourself and look for the signs of wilting, look for the signs of dehydration on your plants," Bieneman said.

Bieneman says succulents, and many native plants, fare well in extreme heat, but you should watch closely for changes in more exotic plant types.

As for yourself, stay hydrated, reduce outdoor activities and check on neighbors.

More resources for staying safe in the extreme heat can be found at health.baltiomrecity.gov.