Several riders needed emergency medical assistance after suffering from heat exhaustion during Monday’s ride, according to a Palo Alto County authorities.

The National Weather Service issued a heat advisory for the western two-thirds of the state for Monday and Tuesday, with temperatures are expected to reach the 90s, with high humidity too. At 4 p.m. on Monday, the temperature in Emmetsburg was 82 degrees with 77 percent humidity, for a heat index of 88 degrees.

Ambulance services were called for riders multiple times Monday toward the end of the route, although Palo Alto County officials didn’t have an each count.

The temperature Tuesday is expected to reach the high 80s or low 90s. The heat index could be about 100 degrees.