Objective: to compare the time for performance of dry and traditional bed bathing and its effects on transcutaneous arterial oxygen saturation and respiratory rates in critical adult patients. Method: pilot study of a randomized, open, crossover clinical trial, performed with 15 adult critically ill patients. Each patient received a dry and a traditional bed bath. Analysis of variance with repeated measures was used, adopting p-value ≤ 0.05. Results: most patients were male (73.3%), white (66.7%), with a mean age of 69.7 years. The dry bath was faster (20.0 minutes) than the traditional bath (30.0 minutes) (p<0.001). There was no significant difference between the patients’ saturation means between baths (p=0.381), with 94.7% for the dry bath and 95.2% for the traditional bath. During the traditional bath, the patients’ respiratory rate mean was higher (24.2 incursions per minute) and statistically different (p<0.001) from the value obtained for the dry bath (20.5 incursions per minute). Conclusion: the dry bath had a shorter duration than did the traditional bath, resulting in less patient exposure. The traditional bed bath had a negative effect on patients’ respiratory rate, increasing it. Brazilian Registry of Clinical Trials (ReBEC): RBR-5qwkqd