* WHAT...Hot conditions with high temperatures up to 85 to 90 degrees expected and low temperatures 58 to 62 degrees. This will pose a moderate risk of heat-related illness. * WHERE...Portions of northwest and west central Washington. * WHEN...From 10 AM Wednesday to 10 PM PDT Thursday. * 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.