Inclusion Criteria:

1. Patient with symptoms of COVID-19 (fever, headache, cough, sore throat, myalgias, arthralgias, shortness of breath, anosmia, fatigue, diarrhea, vomit, or conjunctivitis) meeting criteria for mild or moderate COVID-19 according to the following criteria:

   1. Mild COVID-19: With or without mild pneumonia. Peripheral oxygen arterial saturation (SaO2) greater than or equal to 94% (90% in Mexico City and Guadalajara) at room air. Does not meet criteria of moderate, severe, or critical COVID-19.
   2. Moderate COVID-19: Patient with pneumonia and risk factors for disease progression; meeting all the following: Shortness of breath, peripheral oxygen arterial saturation (SaO2) greater than or equal to 94% (90% in Mexico City and Guadalajara) with a maximum 3 L/min of supplementary oxygen, does not meet criteria for severe, or critical COVID-19.

2. Patient with less than or equal to 5 days from symptom onset

3. Participant understands the intervention and procedures and accepts randomization.

Exclusion Criteria:

1. Suspected or confirmed pregnancy at evaluation

2. Severe decompensation of any of the patient's underlying diseases

3. Previous diagnosis of COVID-19 with complete resolution of symptoms for at least 2 days.

4. Patients meeting criteria for severe or critical COVID-19 at evaluation:

   1. Severe COVID-19 - Patient with ≥1 of the following: tachypnea (≥30 breaths per minute), peripheral oxygen arterial saturation (SaO2) less than or equal to 93% (89% in Mexico City and Guadalajara) with a maximum 3 L/min of supplementary oxygen (patients requiring ≥4 L/min will be considered to have progressed to severe COVID-19), or PaO2/FiO2 ratio <300.
   2. Critical COVID-19 - Patient with ARDS, shock, multiorgan failure, or any other condition requiring admission to an intensive care unit.

Elimination Criteria:

1. Participant retires consent to participate in the study
2. Patient requiring ≥4 L/min of supplementary oxygen in the 24 hours of hospitalization (in the case that randomization occurred in the first 24 hours of hospitalization)
3. Two negative tests against SARS-CoV-2 (a sequential diagnostic strategy will be implemented to reduce losses due to false negative tests).
4. Patient that do not tolerate thermotherapy and requests to stop receiving the intervention.
5. Transfer to another medical unit in the first 5 days of inclusion in the study.