Eddie Dibbs says that he is going to bring along two extra pairs of sneakers, four shirts, eight sets of sweat bands and as many pairs fo socks and towels as he can carry when he plays Jimmy Connors late this afternoon for the $24,000 first prize in the $175,000 Washington Star International tennis championships.

Dibbs saw last night how Washington heat and humidity can affect a tennis match as Manuel Orantes suffered the effects of dehydration and heat exhaustion while playing him in the semifinals.

Dibbs - squishing around the court uncertainly in perspiration, soaked tennis shoes, and having trouble holding on to his racket handle as he served - was trailing, 2-4, in their match at the Washington Tennis Stadium when Orantes started to get groggy.

The temperature on the court was 90 degress, down from 104 in the afternoon, when Connors beat Orantes' Spanish Davis Cup teammate Jose Higueras, 7-6, 6-2, but the air was heavy and stifling.

Orantes became increasingly weary. His touch deserted him. He couldn't serve hard or summon the energy to chase down shots. He ceased being the aggressor and looked punch-drunk on the court.

Drained and dispirited, the stylish left-hander meekly lost the last eight games. The score, in favor of Dibbs, was 7-5, 6-0.

The final will be played at 5 p.m. today because it is being televised live by WTTG-TV-5 in Washington.

Following the singles, Fred McNair IV of Chevy Chase and Raul Ramirez will play Bob Hewitt and Arthur Ashe for the top doubles prize of $9,000.

Ashe-Hewitt defeated the young American team of John McEnroe and Peter Fleming, runners-up to Hewitt and Frew McMillan at Wimbledon, 7-6, 6-3, yesterday afternoon. McNair Ramirez ousted another youthful American pair, Billy Martin and Bill Scanlon, 6-3, 7-6, last night.

"In the middle of the first set, I was feeling very heavy. I couldn't move well. My head was hurting. After that I couldn't get any shots," Orantes said after being examined by Dr. Stephen Haas, the tournament physician.

Orantes stayed in his courtside chair for nearly 10 minutes after the match, trying to revive himself with cold towels. Todd Fullerton, the traveling trainer of the Association of Tennis Professionals, ministered to him and told him to replenish his fluid supply.

"He was just exhausted," said Dibbs, who had been jerked around the court in the early games by Orantes' drop shots and clever variety of pace and spin.

"I don't think I've ever played in worse humidity. My sneakers were dripping wet, and I didn't have a spare pair to change into.The clay just clogged the bottoms of them, so I couldn't get any traction and was slipping all over the place. My hand was so wet it was a joke," continuedDibbs, who twice lost hold of his racket while serving and saw it fly over the net.

"I think the humidity at night here is tougher than the heat during the day. This is the worst I've ever played in. I was soaked by the time we finished warming up before the match."Higueras was also bothered by the weather, though not nearly as dramatically, in his afternoon match against Connors, who played tough, solid clay court tennis to beat him.

"It is very difficult to play in his heat because your hand is wet all the time. When you play a long rally you need three minutes to get normal again," said Higueras, who was nearly as steady from the back court nor as sharp on his passing shots as usual.

Higueras had three set points on Connors' serve at 4-5 in the first set, but Connors served well to escape them.

Ever since he was whupped by Bjorn Borg in the Wimbledon final two weeks ago, his only defeat in 25 matches since mononucleosis side-lined him for seven weeks this spring. Connors has been working on his serve. Zealously.

Taking a leaf from Borg's self-improvement notebook. Connors realized that he had to beef up the one fundamental stroke that he has never been able to rely upon, to make his serve "a weapon, not a hinderance."

"I got out of a couple of deep holes on my serve alone. I had a lot of spin on my second serve, kept it deep, and threw a couple of big serves in there when I needed to," said Connors. "I'm happy with my game all around."

Connors gave a graphic description of what it is like to play in 104-degree heat:

"It feels like you're being plastered with barbecue sauce and you're just waiting to be thrown on th charcoals." said the brash left-hander, who should know as well as anyone how a hotdog feels. "Then you start playing and after about three games you know you're on the charcoals."

Connors hardly ever followed his first serve to the net, as the 25-year-old Higueras expected him to do.

He stayed back and rallied until he got a short ball to pounce on, then came in mostly behind deep backhand approaches down the line.

As in his quarterfinal victory over Hans Gildemeister, Connors was able to pick out short balls and take them on the rise - even high-bouncing top-spinners - slugging them deep for outright winners or effective approaches.

Higueras made far more than his usual quota of unforced errors, especially in the second set, after opportunity had knocked and he had not been there to answer the door.

"I think I didn't play like I can. I missed a lot of easy balls - maybe because Jimmy is faster than most and hits harder," said the placid Spaniard.

"I try to play the same against everybody, but Connors is one of the best players in the world. I tried to keep the ball in play, but it was flying a lot today. I don't know why. Maybe because Jimmy hits with so much pace. This is one of the fastest clay courts we play on, and the ball is lighter than in Europe, so it is better for him."

Higueras, winner of two minor Colgate Grand Prix tournaments this year and a semifinalist in the U.S. Indoors (he lost to Connors, 7-6, 6-3) and the Italian Open, was very much in the match after serving two service winners and two of his six aces in the ninth game of the first set, for a 5-4 lead.

He got to 30-40 on Connors' serve in the next game with a lovely forehand down-the-line passing shot, but Connors saved the first set point by boring to the net and angling away an overhead from the left sideline.

Higueras had two more set points but couldn't pressure Connors, who saved them with a good serve wide to the backhand that the Spaniard choked into the bottom of the net and a fine backhand drop volley.

In the tie breaker that decided the set. Higueras started with an ace and took a 2-1 lead with a searing back hand down-the-line pass, but then Connors took control with a sharply-angled backhand cross-court pass that even Higueras applauded.

Connors won four points in a row and the tie breaker, 7-4, and broke in the sixth and eight games of the second set as Higueras' stroking became increasingly weary.