NORTHAMPTON — Heat intensifies Evan Rudzik’s traffic enforcement shifts: his muscles get fatigued faster, his breath feels heavier and his sweat causes his florescent uniform to stick to his back and legs.

So after six hours of directing traffic on Monday, as temperatures soared into the high 90s and humidity rose to unbearable levels along with it, Rudzik’s GoCool cooling towel stopped fending off the heat emanating from the asphalt of Main Street.

However, this weather barely bothers Officer Gilberto “Chico” Jimenez, whose directing traffic just down the road from Rudzik. He’s from Puerto Rico, where it’s regularly hot and humid, so even when the heat index soars above 100 — like it did on Monday and will continue to wave between 105 and 110 on Tuesday — Jimenez worries more about the other officers out on duty.

“In this condition, I like to be considerate of ot hers,” Jimenez said, who’s been switching back and forth with Tennison Clarke — another traffic enforcer from a hot climate — so that his superior can take more frequent breaks.

Summer is off to a scorching start this week with the season’s first heat wave. With extreme heat in the forecast for at least the next two days, followed by warm evening conditions that prevent homes and people from cooling down, cities and towns across Hampshire County are warning residents to avoid the outdoors, drink lots of water and seek air-conditioned areas.

“There’s not much of a breeze, which can be very depleting,” Clarke said while directing traffic outside of Forbes Library. “When there’s heat and a breeze, it’s relaxing, but when it’s hot, humid and there’s no break [in the hot air], that’s a different story.”

According to the National Weather Service office in Norton, the heat index on Tuesday will hover between 105 and 110, with temperatures possibly reaching the triple digits. Wednesday will be relatively cooler, with a heat index and temperatures in the lower 90s.

NWS meteorologist Andy Nash points to the heat dome, a large area of high pressure throughout the atmosphere, covering the Midwest and Eastern United States as the cause of these extreme temperatures. Air sinks in areas of high pressure, clearing the sky of any clouds.

“Sinking air means you get a lot of sun and during the summer time the sun is really strong, has a lot of heat and it feeds on itself,” Nash said.

Humidity also contributes to heat by preventing the body from cooling as effectively. People emit sweat to cool down, and when the sweat evaporates, the atmosphere absorbs that heat from the body. When it’s humid, that evaporation happens much slower, if at all.

“That’s where people can have issues with heat illnesses like heat stroke and heat exhaustion,” Nash said.

Reservoir refuge

UMass graduate students Bella Moses and Haley Harris hail from New Mexico and southern California, where the summer weather is defined by the desert’s dry heat. On Monday they were finding refuge from the heat dome at the Hadley Reservoir with their friends, but Harris said she already feels like she’s in a wet towel before stepping foot in the forested lake. Moses and Mary Luna, who has lived in the intense Texas heat, actually prefer the humid conditions.

“Not when it’s this hot, but the humidity does not bother me as much as other people,” Moses said. “I think, because I’m from the desert, I know the other option.”

The intense heat will last until Thursday, when incoming storms will push the heat dome farther east, Nash said. While the lower pressure front ushers out the worst of the heat wave and cools temperatures, Nash expects humid, hot thunderstorms and rain to punctuate the weekend.

Cooling centers

In preparation for the heat wave, cities and towns in the area opened up public buildings as cooling centers. Residents can seek air conditioning in libraries, senior centers and public safety lobbies during hours of operation, but some cities and towns have extra buildings open to prevent heat-related illnesses.

“Heat stress is a serious condition that poses a health threat to many people, particularly the elderly and young children,” Amherst officials said in a statement. “Heat stress places a strain on the body, and if the strain becomes too great, it can cause serious and permanent damage, even death.”

Hilltown CDC Executive Director Dave Christopolis said the economic development agency checks on their senior tenants in public housing during abnormally high heat to ensure this vulnerable population has access to air conditioning units. Most seniors centers and libraries are open as cooling centers in the smaller rural towns.

“The biggest concern up here is people who are in their homes who are alone,” he said. “One of our programs does in-home visits to seniors, so we’ve been doing check-ins on seniors.”

Amherst will keep Bangs Community Center at 70 Boltwood Walk open from 8 a.m. to 4 p.m. for anyone who wants to cool down. Munson Memorial Library, at 1046 S. East St., and North Amherst Library, 8 Montague Road, will also serve as cooling centers. Munson Memorial will be open from 2 to 5:30 p.m. on Tuesday and 2 to 7:30 p.m. on Wednesday.

Northampton offers a total of eight cooling centers, including Thrones Marketplace with a water bottle filling station. Forbes Library and Lillie Library have air conditioning on during business hours of 10 a.m. to 8 p.m. and 10 a.m. to 5 p.m., respectively. Manna Soup Kitchen serves as a cooling center in addition to a food pantry this week from 10 a.m. to 3 p.m. The CSO Shelter on 29 Industrial St. East and Northampton Senior Center will both accept hot visitors from 8 a.m. to 4 p.m. The Northampton Police Station will remain open 24/7 for those who need air conditioning overnight.

During regular business hours, Holyoke’s War Memorial Building at 310 Appleton St., Center for Human Development (CHD) at 696 Dwight St., the Holyoke Public Library at 250 Chestnut St. and Holyoke Senior Center at 291 Pine St. are cooling centers for the city.

In South Hadley, all public buildings serve as cooling centers, including the Fire District buildings. Belchertown has opened the Senior Center for any resident looking to stay out of the sun. Easthampton established a cooling center at their Council on Aging from 8 a.m. to 4 p.m. Hadley has three cooling centers; Hadley Senior Center, the Hadley Public Library and the Hampshire Mall.

Emilee Klein can be reached at eklein@gazettenet.com.