* WHAT...Hot conditions with high temperatures up to 85 to 90 degrees expected. This will pose a moderate risk of heat-related illness. * WHERE...Portions of northwest and west central Washington. * WHEN...Until 10 PM PDT this evening. * IMPACTS...Heat will significantly increase the risk of heat-related illnesses for those who are sensitive to heat, especially those without effective cooling or adequate hydration. * ADDITIONAL DETAILS...Warm temperatures overnight will bring limited relief for the interior.