The National Weather Service has issued a Heat Advisory for coastal areas including San Francisco over the Labor Day Weekend.

To beat the heat, some Bay Area schools are closing early; Pacific Gas & Electric has advised customers that service interruptions are a strong possibility in the afternoon.

Although it'll be hotter in the East Bay and on the Peninsula, temperatures could rise as high as 99 degrees in some parts of the city this afternoon, according to some forecasts.

Smoke from several wildfires in Nevada, Oregon and Northern California ha drifted over the city, compounding the Spare The Air days already declared for this weekend.

Those conditions mean that heat illnesses are possible and put older adults, children and people who are sick especially at risk. The San Francisco Department of Emergency Management advises residents to follow guidelines from the National Weather Service.

Eat lunch indoors! Temps right now in the 100s pic.twitter.com/dGx9brVOyo

— Frances Dinglasan (@FrancesABC7) September 1, 2017

To prevent heat sickness, follow these steps:

• Drink fluids frequently throughout the day, before you feel thirsty.
• Check on the elderly regularly.
• Limit outdoor activity, especially during the hottest part of the day.
• Take frequent breaks in the shade when spending time outside.
• Wear light‐colored, light‐weight clothing and a hat.
• Avoid alcoholic beverages and caffeinated drinks.
• If you do not have an air conditioner, go to a cooler place such as a store, mall, museum, or movie theater, or, visit a cooling center.
• Bathing or showering with cool (not cold) water can be helpful for those able to do so safely.

Please plan now for the heat this weekend. Include your pets, children, and share with friends. pic.twitter.com/wEaDeIB3dm

— San Francisco Fire (@sffdpio) August 31, 2017

You can also check out the additional tips from the Department of Public Health. If you or someone you know feels weak or faint, go to a cool place and drink water. If there are no signs of improvement, call a doctor or 911. Paleness, tiredness, weakness, dizziness, headache, fainting, muscle cramps or heavy sweating are all signs of heat exhaustion.

Heat Advisory issued for #SF: Call 9-1-1 immediately if you or someone you know has signs of Heat Stroke. pic.twitter.com/hsSuJGh5dd

— San Francisco DEM (@SF_emergency) September 1, 2017

If you are looking for a safer option to cool down than swimming in the ocean, Rec and Parks operates nine public pools.

A map also shows a list of the city's cooling centers, which includes public libraries.

And SF's Animal Care & Control (ACC) reminds the public not to leave pets in cars during hot weather, as cars will heat up quickly. If anyone sees animals in distress, ACC can be reached at 415-554-9400.