Older adults and children are most vulnerable during heat waves like the one currently hitting Southern California.

PASADENA, Calif. (KABC) — As the extreme heat warning continues in Southern California, it is important to protect everyone, especially the most vulnerable.

Elderly people and children should be especially careful.

And for many seniors, air conditioning is either unavailable or too expensive to use.

Holly Reed, 80, spends his days filling himself with ice water. He has taken refuge at the Pasadena Senior Center because he doesn’t want to turn on the air conditioning in his home.

“I don’t use it because I can’t afford it,” Reed says. “You’re afraid you’re going to run out of money at the end of the month because you can’t afford to pay anything.”

Like many seniors, Reed lives alone. A climate vulnerability map of Los Angeles County shows that the places where most seniors live are also the areas hardest hit by extreme heat days.

Dr. Roger Yang, an emergency room specialist at Huntington Health, an affiliate of Cedars Sinai, says that during the scorching temperatures, he typically sees one patient a day with heat exhaustion.

“Maybe in these times they should ask their family to look after them. Drinking water is very important and I know many of our elders don’t do it,” Yang said.

But older patients are most likely to suffer more severe forms of heat-related illness.

“By the time you have heat stroke, most of these people are confused and not acting normally. Patients start to suffer multiple organ failure, which can lead to liver failure,” Yang said.

For Pasadena seniors who can’t leave their homes, the Pasadena Senior Center offers in-person check-ins during meal deliveries and through regular phone calls.

“This phone call to a number of seniors who have asked to be called continues throughout the week to make sure everyone is OK,” said Pamela Kaye of the Pasadena Senior Center.

Older people generally don’t need to be active to suffer from heat-related illness, but in hot weather it’s the exertion that gets many children and young athletes into trouble.

Children are more vulnerable because they do not cool themselves as effectively as adults.

The Los Angeles County climate vulnerability map shows high concentrations of children living in areas of extreme heat.

Dr. Yang says it’s up to adults to watch for signs.

“They’ll feel dizzy,” Yang said. “They’ll feel nauseous. If they’re sweating profusely, that’s probably a sign they’re suffering from heat exhaustion.”

And these warning signs apply to adults as well.

Experts say if you know a senior or older adult who doesn’t have air conditioning, check on them and make sure they’re staying hydrated and know not to wait until they’re thirsty to drink.

Here’s a list of Los Angeles County cooling centers and a way to find a Los Angeles County pool nearest you.

Also check out the Los Angeles “Beat the Heat” website for more information on the signs and symptoms of heat-related illness.